Comparing Some Strategies from Easy Volatility Investing, and the Table.Drawdowns Command

This post will be about comparing strategies from the paper “Easy Volatility Investing”, along with a demonstration of R’s table.Drawdowns command.

First off, before going further, while I think the execution assumptions found in EVI don’t lend the strategies well to actual live trading (although their risk/reward tradeoffs also leave a lot of room for improvement), I think these strategies are great as benchmarks.

So, some time ago, I did an out-of-sample test for one of the strategies found in EVI, which can be found here.

Using the same source of data, I also obtained data for SPY (though, again, AlphaVantage can also provide this service for free for those that don’t use Quandl).

Here’s the new code.

```require(downloader)
require(quantmod)
require(PerformanceAnalytics)
require(TTR)
require(Quandl)
require(data.table)

VIXdates <- VIX\$Date
VIX\$Date <- NULL; VIX <- xts(VIX, order.by=as.Date(VIXdates, format = '%m/%d/%Y'))

ma_vRatio <- SMA(Cl(VIX)/Cl(vxv), 10)
xivSigVratio <- ma_vRatio < 1
vxxSigVratio <- ma_vRatio > 1

# V-ratio (VXV/VXMT)
vRatio <- lag(xivSigVratio) * xivRets + lag(vxxSigVratio) * vxxRets
# vRatio <- lag(xivSigVratio, 2) * xivRets + lag(vxxSigVratio, 2) * vxxRets

spy <- Quandl("EOD/SPY", start_date='1990-01-01', type = 'xts')
histVol <- runSD(spyRets, n = 10, sample = FALSE) * sqrt(252) * 100
vixDiff <- Cl(VIX) - histVol
maVixDiff <- SMA(vixDiff, 5)

vrpXivSig <- maVixDiff > 0
vrpVxxSig <- maVixDiff < 0
vrpRets <- lag(vrpXivSig, 1) * xivRets + lag(vrpVxxSig, 1) * vxxRets

obsCloseMomentum <- magicThinking # from previous post

compare <- na.omit(cbind(xivRets, obsCloseMomentum, vRatio, vrpRets))
colnames(compare) <- c("BH_XIV", "DDN_Momentum", "DDN_VRatio", "DDN_VRP")
```

So, an explanation: there are four return streams here–buy and hold XIV, the DDN momentum from a previous post, and two other strategies.

The simpler one, called the VRatio is simply the ratio of the VIX over the VXV. Near the close, check this quantity. If this is less than one, buy XIV, otherwise, buy VXX.

The other one, called the Volatility Risk Premium strategy (or VRP for short), compares the 10 day historical volatility (that is, the annualized running ten day standard deviation) of the S&P 500, subtracts it from the VIX, and takes a 5 day moving average of that. Near the close, when that’s above zero (that is, VIX is higher than historical volatility), go long XIV, otherwise, go long VXX.

Again, all of these strategies are effectively “observe near/at the close, buy at the close”, so are useful for demonstration purposes, though not for implementation purposes on any large account without incurring market impact.

Here are the results, since 2011 (that is, around the time of XIV’s actual inception):

To note, both the momentum and the VRP strategy underperform buying and holding XIV since 2011. The VRatio strategy, on the other hand, does outperform.

Here’s a summary statistics function that compiles some top-level performance metrics.

```stratStats <- function(rets) {
stats <- rbind(table.AnnualizedReturns(rets), maxDrawdown(rets))
stats[5,] <- stats[1,]/stats[4,]
stats[6,] <- stats[1,]/UlcerIndex(rets)
rownames(stats)[4] <- "Worst Drawdown"
rownames(stats)[5] <- "Calmar Ratio"
rownames(stats)[6] <- "Ulcer Performance Index"
return(stats)
}
```

And the result:

```> stratStats(compare['2011::'])
BH_XIV DDN_Momentum DDN_VRatio   DDN_VRP
Annualized Return         0.3801000    0.2837000  0.4539000 0.2572000
Annualized Std Dev        0.6323000    0.5706000  0.6328000 0.6326000
Annualized Sharpe (Rf=0%) 0.6012000    0.4973000  0.7172000 0.4066000
Worst Drawdown            0.7438706    0.6927479  0.7665093 0.7174481
Calmar Ratio              0.5109759    0.4095285  0.5921650 0.3584929
Ulcer Performance Index   1.1352168    1.2076995  1.5291637 0.7555808
```

To note, all of the benchmark strategies suffered very large drawdowns since XIV’s inception, which we can examine using the table.Drawdowns command, as seen below:

```> table.Drawdowns(compare[,1]['2011::'], top = 5)
From     Trough         To   Depth Length To Trough Recovery
1 2011-07-08 2011-11-25 2012-11-26 -0.7439    349        99      250
2 2015-06-24 2016-02-11 2016-12-21 -0.6783    379       161      218
3 2014-07-07 2015-01-30 2015-06-11 -0.4718    236       145       91
4 2011-02-15 2011-03-16 2011-04-20 -0.3013     46        21       25
5 2013-04-15 2013-06-24 2013-07-22 -0.2877     69        50       19
> table.Drawdowns(compare[,2]['2011::'], top = 5)
From     Trough         To   Depth Length To Trough Recovery
1 2014-07-07 2016-06-27 2017-03-13 -0.6927    677       499      178
2 2012-03-27 2012-06-13 2012-09-13 -0.4321    119        55       64
3 2011-10-04 2011-10-28 2012-03-21 -0.3621    117        19       98
4 2011-02-15 2011-03-16 2011-04-21 -0.3013     47        21       26
5 2011-06-01 2011-08-04 2011-08-18 -0.2723     56        46       10
> table.Drawdowns(compare[,3]['2011::'], top = 5)
From     Trough         To   Depth Length To Trough Recovery
1 2014-01-23 2016-02-11 2017-02-14 -0.7665    772       518      254
2 2011-09-13 2011-11-25 2012-03-21 -0.5566    132        53       79
3 2012-03-27 2012-06-01 2012-07-19 -0.3900     80        47       33
4 2011-02-15 2011-03-16 2011-04-20 -0.3013     46        21       25
5 2013-04-15 2013-06-24 2013-07-22 -0.2877     69        50       19
> table.Drawdowns(compare[,4]['2011::'], top = 5)
From     Trough         To   Depth Length To Trough Recovery
1 2015-06-24 2016-02-11 2017-10-11 -0.7174    581       161      420
2 2011-07-08 2011-10-03 2012-02-03 -0.6259    146        61       85
3 2014-07-07 2014-12-16 2015-05-21 -0.4818    222       115      107
4 2013-02-20 2013-07-08 2014-06-10 -0.4108    329        96      233
5 2012-03-27 2012-06-01 2012-07-17 -0.3900     78        47       31
```

Note that the table.Drawdowns command only examines one return stream at a time. Furthermore, the top argument specifies how many drawdowns to look at, sorted by greatest drawdown first.

One reason I think that these strategies seem to suffer the drawdowns they do is that they’re either all-in on one asset, or its exact opposite, with no room for error.

One last thing, for the curious, here is the comparison with my strategy since 2011 (essentially XIV inception) benchmarked against the strategies in EVI (which I have been trading with live capital since September, and have recently opened a subscription service for):

```stratStats(compare['2011::'])
QST_vol    BH_XIV DDN_Momentum DDN_VRatio   DDN_VRP
Annualized Return          0.8133000 0.3801000    0.2837000  0.4539000 0.2572000
Annualized Std Dev         0.3530000 0.6323000    0.5706000  0.6328000 0.6326000
Annualized Sharpe (Rf=0%)  2.3040000 0.6012000    0.4973000  0.7172000 0.4066000
Worst Drawdown             0.2480087 0.7438706    0.6927479  0.7665093 0.7174481
Calmar Ratio               3.2793211 0.5109759    0.4095285  0.5921650 0.3584929
Ulcer Performance Index   10.4220721 1.1352168    1.2076995  1.5291637 0.7555808
```

NOTE: I am currently looking for networking and full-time opportunities related to my skill set. My LinkedIn profile can be found here.

Launching My Subscription Service

After gauging interest from my readers, I’ve decided to open up a subscription service. I’ll copy and paste the FAQs, or my best attempt at trying to answer as many questions as possible ahead of time, and may answer more in the future.

I’m choosing to use Patreon just to outsource all of the technicalities of handling subscriptions and creating a centralized source to post subscription-based content.

FAQs (copied from the subscription page):

*****

Thank you for visiting. After gauging interest from my readership on my main site (www.quantstrattrader.wordpress.com), I created this as a subscription page for quantitative investment strategies, with the goal of having subscribers turn their cash into more cash, net of subscription fees (hopefully). The systems I develop come from a background of learning from experienced quantitative trading professionals, and senior researchers at large firms. The current system I initially published a prototype for several years back and watched it being tracked, before finally starting to deploy my own capital earlier this year, and making the most recent modifications even more recently.

And while past performance doesn’t guarantee future results and the past doesn’t repeat itself, it often rhymes, so let’s turn money into more money.

​What is the subscription price for this strategy?

​Currently, after gauging interest from readers and doing research based on other sites, the tentative pricing is \$50/month. As this strategy builds a track record, that may be subject to change in the future, and notifications will be made in such an event.

What is the description of the strategy?

The strategy is mainly a short volatility system that trades XIV, ZIV, and VXX. As far as volatility strategies go, it’s fairly conservative in that it uses several different checks in order to ensure a position.

What is the strategy’s edge?

In two words: risk management. Essentially, there are a few separate criteria to select an investment, and the system spends a not-insignificant time with no exposure when some of these criteria provide contradictory signals. Furthermore, the system uses disciplined methodologies in its construction in order to avoid unnecessary free parameters, and to keep the strategy as parsimonious as possible.

Yes.

When was the in-sample training period for this system?

A site that no longer updates its blog (volatility made simple) once tracked a more rudimentary strategy that I wrote about several years ago. I was particularly pleased with the results of that vetting, and recently have received input to improve my system to a much greater degree, as well as gained the confidence to invest live capital into it.

How many trades per year does the system make?

In the backtest from April 20, 2008 through the end of 2016, the system made 187 transactions in XIV (both buy and sell), 160 in ZIV, and 52 in VXX. Meaning over the course of approximately 9 years, there was on average 43 transactions per year. In some cases, this may simply be switching from XIV to ZIV or vice versa. In other words, trades last approximately a week (some may be longer, some shorter).

When will signals be posted?

Signals will be posted sometime between 12 PM and market close (4 PM EST). In backtesting, they are tested as market on close orders, so individuals assume any risk/reward by executing earlier.

How often is this system in the market?

About 56%. However, over the course of backtesting (and live trading), only about 9% of months have zero return.

What are the distribution of winning, losing, and zero return months?

As of late October 2017, there have been about 65% winning months (with an average gain of 12.8%), 26% losing months (with an average loss of 4.9%), and 9% zero months.

What are some other statistics about the strategy?

Since 2011 (around the time that XIV officially came into inception as opposed to using synthetic data), the strategy has boasted an 82% annualized return, with a 24.8% maximum drawdown and an annualized standard deviation of 35%. This means a Sharpe ratio (return to standard deviation) higher than 2, and a Calmar ratio higher than 3. It also has an Ulcer Performance Index of 10.

What are the strategy’s worst drawdowns?

Since 2011 (again, around the time of XIV’s inception), the largest drawdown was 24.8%, starting on October 31, 2011, and making a new equity high on January 12, 2012. The longest drawdown started on August 21, 2014 and recovered on April 10, 2015, and lasted for 160 trading days.

Will the subscription price change in the future?

If the strategy continues to deliver strong returns, then there may be reason to increase the price so long as the returns bear it out.

Can a conservative risk signal be provided for those who might not be able to tolerate a 25% drawdown?

A variant of the strategy that targets about half of the annualized standard deviation of the strategy boasts a 40% annualized return for about 12% drawdown since 2011. Overall, this has slightly higher reward to risk statistics, but at the cost of cutting aggregate returns in half.

Can’t XIV have a termination event?

This refers to the idea of the XIV ETN terminating if it loses 80% of its value in a single day. To give an idea of the likelihood of this event, using synthetic data, the XIV ETN had a massive drawdown of 92% over the course of the 2008 financial crisis. For the history of that synthetic (pre-inception) and realized (post-inception) data, the absolute worst day was a down day of 26.8%. To note, the strategy was not in XIV during that day.

What was the strategy’s worst day?

On September 16, 2016, the strategy lost 16% in one day. This was at the tail end of a stretch of positive days that made about 40%.

What are the strategy’s risks?

The first risk is that given that this strategy is naturally biased towards short volatility, that it can have potential for some sharp drawdowns due to the nature of volatility spikes. The other risk is that given that this strategy sometimes spends its time in ZIV, that it will underperform XIV on some good days. This second risk is a consequence of additional layers of risk management in the strategy.

How complex is this strategy?

Not overly. It’s only slightly more complex than a basic momentum strategy when counting free parameters, and can be explained in a couple of minutes.

Does this strategy use any complex machine learning methodologies?

No. The data requirements for such algorithms and the noise in the financial world make it very risky to apply these methodologies, and research as of yet did not bear fruit to justify incorporating them.

Will instrument volume ever be a concern (particularly ZIV)?

According to one individual who worked on the creation of the original VXX ETN (and by extension, its inverse, XIV), new shares of ETNs can be created by the issuer (in ZIV’s case, Credit Suisse) on demand. In short, the concern of volume is more of a concern of the reputability of the person making the request. In other words, it depends on how well the strategy does.

Can the strategy be held liable/accountable/responsible for a subscriber’s loss/drawdown?

​Let this serve as a disclaimer: by subscribing, you agree to waive any legal claim against the strategy, or its creator(s) in the event of drawdowns, losses, etc. The subscription is for viewing the output of a program, and this service does not actively manage a penny of subscribers’ actual assets. Subscribers can choose to ignore the strategy’s signals at a moment’s notice at their discretion. The program’s output should not be thought of as the investment advice coming from a CFP, CFA, RIA, etc.

Why should these signals be trusted?

Because my work on other topics has been on full, public display for several years. Unlike other websites, I have shown “bad backtests”, thus breaking the adage of “you’ll never see a bad backtest”. I have shown thoroughness in my research, and the same thoroughness has been applied towards this system as well. Until there is a longer track record such that the system can stand on its own, the trust in the system is the trust in the system’s creator.

Who is the intended audience for these signals?

The intended audience is individual, retail investors with a certain risk tolerance, and is priced accordingly.

​Isn’t volatility investing very risky?

​It’s risky from the perspective of the underlying instrument having the capacity to realize very large drawdowns (greater than 60%, and even greater than 90%). However, from a purely numerical standpoint, the company taking over so much of shopping, Amazon, since inception has had a 37.1% annualized rate of return, a standard deviation of 61.5%, a worst drawdown of 94%, and an Ulcer Performance Index of 0.9. By comparison, XIV, from 2008 (using synthetic data), has had a 35.5% annualized rate of return, a standard deviation of 57.7%, a worst drawdown of 92%, and an Ulcer Performance Index of 0.6. If Amazon is considered a top-notch asset, then from a quantitative comparison, a system looking to capitalize on volatility bets should be viewed from a similar perspective. To be sure, the strategy’s performance vastly outperforms that of buying and holding XIV (which nobody should do). However, the philosophy of volatility products being much riskier than household tech names just does not hold true unless the future wildly differs from the past.

​Is there a possibility for collaborating with other strategy creators?

​Feel free to contact me at my email ilya.kipnis@gmail.com to discuss that possibility. I request a daily stream of returns before starting any discussion.

Why Patreon?

Because past all the artsy-craftsy window dressing and interesting choice of vocabulary, Patreon is simply a platform that processes payments and creates a centralized platform from which to post subscription-based content, as opposed to maintaining mailing lists and other technical headaches. Essentially, it’s simply a way to outsource the technical end of running a business, even if the window dressing is a bit unorthodox.

***

NOTE: I am currently interested in networking and full-time roles based on my skills. My LinkedIn profile can be found here.

The Return of Free Data and Possible Volatility Trading Subscription

This post will be about pulling free data from AlphaVantage, and gauging interest for a volatility trading subscription service.

So first off, ever since the yahoos at Yahoo decided to turn off their free data, the world of free daily data has been in somewhat of a dark age. Well, thanks to http://blog.fosstrading.com/2017/10/getsymbols-and-alpha-vantage.html#gpluscommentsJosh Ulrich, Paul Teetor, and other R/Finance individuals, the latest edition of quantmod (which can be installed from CRAN) now contains a way to get free financial data from AlphaVantage since the year 2000, which is usually enough for most backtests, as that date predates the inception of most ETFs.

Here’s how to do it.

First off, you need to go to alphaVantage, register, and https://www.alphavantage.co/support/#api-keyget an API key.

Once you do that, downloading data is simple, if not slightly slow. Here’s how to do it.

```require(quantmod)

getSymbols('SPY', src = 'av', adjusted = TRUE, output.size = 'full', api.key = YOUR_KEY_HERE)
```

And the results:

```> head(SPY)
SPY.Open SPY.High SPY.Low SPY.Close SPY.Volume SPY.Adjusted
2000-01-03   148.25   148.25 143.875  145.4375    8164300     104.3261
2000-01-04   143.50   144.10 139.600  139.8000    8089800     100.2822
2000-01-05   139.90   141.20 137.300  140.8000    9976700     100.9995
2000-01-06   139.60   141.50 137.800  137.8000    6227200      98.8476
2000-01-07   140.30   145.80 140.100  145.8000    8066500     104.5862
2000-01-10   146.30   146.90 145.000  146.3000    5741700     104.9448
```

Which means if any one of my old posts on asset allocation has been somewhat defunct thanks to bad yahoo data, it will now work again with a slight modification to the data input algorithms.

Beyond demonstrating this routine, one other thing I’d like to do is to gauge interest for a volatility signal subscription service, for a system I have personally started trading a couple of months ago.

Simply, I have seen other websites with subscription services with worse risk/reward than the strategy I currently trade, which switches between XIV, ZIV, and VXX. Currently, the equity curve, in log 10, looks like this:

That is, \$1000 in 2008 would have become approximately \$1,000,000 today, if one was able to trade this strategy since then.

Since 2011 (around the time of inception for XIV), the performance has been:

```
Performance
Annualized Return         0.8265000
Annualized Std Dev        0.3544000
Annualized Sharpe (Rf=0%) 2.3319000
Worst Drawdown            0.2480087
Calmar Ratio              3.3325450
```

Considering that some websites out there charge upwards of \$50 a month for either a single tactical asset rotation strategy (and a lot more for a combination) with inferior risk/return profiles, or a volatility strategy that may have had a massive and historically record-breaking drawdown, I was hoping to gauge a price point for what readers would consider paying for signals from a better strategy than those.

NOTE: I am currently interested in networking and am seeking full-time opportunities related to my skill set. My LinkedIn profile can be found here.

The Kelly Criterion — Does It Work?

This post will be about implementing and investigating the running Kelly Criterion — that is, a constantly adjusted Kelly Criterion that changes as a strategy realizes returns.

For those not familiar with the Kelly Criterion, it’s the idea of adjusting a bet size to maximize a strategy’s long term growth rate. Both https://en.wikipedia.org/wiki/Kelly_criterionWikipedia and Investopedia have entries on the Kelly Criterion. Essentially, it’s about maximizing your long-run expectation of a betting system, by sizing bets higher when the edge is higher, and vice versa.

There are two formulations for the Kelly criterion: the Wikipedia result presents it as mean over sigma squared. The Investopedia definition is P-[(1-P)/winLossRatio], where P is the probability of a winning bet, and the winLossRatio is the average win over the average loss.

In any case, here are the two implementations.

```investoPediaKelly <- function(R, kellyFraction = 1, n = 63) {
signs <- sign(R)
posSigns <- signs; posSigns[posSigns < 0] <- 0
negSigns <- signs; negSigns[negSigns > 0] <- 0; negSigns <- negSigns * -1
probs <- runSum(posSigns, n = n)/(runSum(posSigns, n = n) + runSum(negSigns, n = n))
posVals <- R; posVals[posVals < 0] <- 0
negVals <- R; negVals[negVals > 0] <- 0;
wlRatio <- (runSum(posVals, n = n)/runSum(posSigns, n = n))/(runSum(negVals, n = n)/runSum(negSigns, n = n))
kellyRatio <- probs - ((1-probs)/wlRatio)
out <- kellyRatio * kellyFraction
return(out)
}

wikiKelly <- function(R, kellyFraction = 1, n = 63) {
return(runMean(R, n = n)/runVar(R, n = n)*kellyFraction)
}
```

Let’s try this with some data. At this point in time, I’m going to show a non-replicable volatility strategy that I currently trade.

For the record, here are its statistics:

```                              Close
Annualized Return         0.8021000
Annualized Std Dev        0.3553000
Annualized Sharpe (Rf=0%) 2.2574000
Worst Drawdown            0.2480087
Calmar Ratio              3.2341613
```

Now, let’s see what the Wikipedia version does:

```badKelly <- out * lag(wikiKelly(out), 2)
```

The results are simply ridiculous. And here would be why: say you have a mean return of .0005 per day (5 bps/day), and a standard deviation equal to that (that is, a Sharpe ratio of 1). You would have 1/.0005 = 2000. In other words, a leverage of 2000 times. This clearly makes no sense.

The other variant is the more particular Investopedia definition.

```invKelly <- out * lag(investKelly(out), 2)
charts.PerformanceSummary(invKelly)
```

Looks a bit more reasonable. However, how does it stack up against not using it at all?

```compare <- na.omit(cbind(out, invKelly))
charts.PerformanceSummary(compare)
```

Turns out, the fabled Kelly Criterion doesn’t really change things all that much.

For the record, here are the statistical comparisons:

```                               Base     Kelly
Annualized Return         0.8021000 0.7859000
Annualized Std Dev        0.3553000 0.3588000
Annualized Sharpe (Rf=0%) 2.2574000 2.1903000
Worst Drawdown            0.2480087 0.2579846
Calmar Ratio              3.2341613 3.0463063
```

NOTE: I am currently looking for my next full-time opportunity, preferably in New York City or Philadelphia relating to the skills I have demonstrated on this blog. My LinkedIn profile can be found here. If you know of such opportunities, do not hesitate to reach out to me.

Leverage Up When You’re Down?

This post will investigate the idea of reducing leverage when drawdowns are small, and increasing leverage as losses accumulate. It’s based on the idea that whatever goes up must come down, and whatever comes down generally goes back up.

I originally came across this idea from this blog post.

So, first off, let’s write an easy function that allows replication of this idea. Essentially, we have several arguments:

One: the default leverage (that is, when your drawdown is zero, what’s your exposure)? For reference, in the original post, it’s 10%.

Next: the various leverage levels. In the original post, the leverage levels are 25%, 50%, and 100%.

And lastly, we need the corresponding thresholds at which to apply those leverage levels. In the original post, those levels are 20%, 40%, and 55%.

So, now we can create a function to implement that in R. The idea being that we have R compute the drawdowns, and then use that information to determine leverage levels as precisely and frequently as possible.

Here’s a quick piece of code to do so:

```require(xts)
require(PerformanceAnalytics)

drawdownLev <- function(rets, defaultLev = .1, levs = c(.25, .5, 1), ddthresh = c(-.2, -.4, -.55)) {
# compute drawdowns
dds <- PerformanceAnalytics:::Drawdowns(rets)

# initialize leverage to the default level
dds\$lev <- defaultLev

# change the leverage for every threshold
for(i in 1:length(ddthresh)) {

# as drawdowns go through thresholds, adjust leverage
dds\$lev[dds\$Close < ddthresh[i]] <- levs[i]
}

# compute the new strategy returns -- apply leverage at tomorrow's close
out <- rets * lag(dds\$lev, 2)

# return the leverage and the new returns
leverage <- dds\$lev
colnames(leverage) <- c("DDLev_leverage")
return(list(leverage, out))
}
```

So, let’s replicate some results.

```require(downloader)
require(xts)
require(PerformanceAnalytics)

destfile="longXIV.txt")

xivRets <- Return.calculate(Cl(xiv))

xivDDlev <- drawdownLev(xivRets, defaultLev = .1, levs = c(.25, .5, 1), ddthresh = c(-.2, -.4, -.55))
compare <- na.omit(cbind(xivDDlev[[2]], xivRets))
colnames(compare) <- c("XIV_DD_leverage", "XIV")

charts.PerformanceSummary(compare['2011::2016'])
```

And our results look something like this:

```                          XIV_DD_leverage       XIV
Annualized Return               0.2828000 0.2556000
Annualized Std Dev              0.3191000 0.6498000
Annualized Sharpe (Rf=0%)       0.8862000 0.3934000
Worst Drawdown                  0.4870604 0.7438706
Calmar Ratio                    0.5805443 0.3436668
```

That said, what would happen if one were to extend the data for all available XIV data?

```> rbind(table.AnnualizedReturns(compare), maxDrawdown(compare), CalmarRatio(compare))
XIV_DD_leverage       XIV
Annualized Return               0.1615000 0.3319000
Annualized Std Dev              0.3691000 0.5796000
Annualized Sharpe (Rf=0%)       0.4375000 0.5727000
Worst Drawdown                  0.8293650 0.9215784
Calmar Ratio                    0.1947428 0.3601385
```

A different story.

In this case, I think the takeaway is that such a mechanism does well when the drawdowns for the benchmark in question occur sharply, so that the lower exposure protects from those sharp drawdowns, and then the benchmark spends much of the time in a recovery mode, so that the increased exposure has time to earn outsized returns, and then draws down again. When the benchmark continues to see drawdowns after maximum leverage is reached, or continues to perform well when not in drawdown, such a mechanism falls behind quickly.

As always, there is no free lunch when it comes to drawdowns, as trying to lower exposure in preparation for a correction will necessarily mean forfeiting a painful amount of upside in the good times, at least as presented in the original post.

NOTE: I am currently looking for my next full-time opportunity, preferably in New York City or Philadelphia relating to the skills I have demonstrated on this blog. My LinkedIn profile can be found here. If you know of such opportunities, do not hesitate to reach out to me.

Let’s Talk Drawdowns (And Affiliates)

This post will be directed towards those newer in investing, with an explanation of drawdowns–in my opinion, a simple and highly important risk statistic.

Would you invest in this?

As it turns out, millions of people do, and did. That is the S&P 500, from 2000 through 2012, more colloquially referred to as “the stock market”. Plenty of people around the world invest in it, and for a risk to reward payoff that is very bad, in my opinion. This is an investment that, in ten years, lost half of its value–twice!

At its simplest, an investment–placing your money in an asset like a stock, a savings account, and so on, instead of spending it, has two things you need to look at.

First, what’s your reward? If you open up a bank CD, you might be fortunate to get 3%. If you invest it in the stock market, you might get 8% per year (on average) if you held it for 20 years. In other words, you stow away \$100 on January 1st, and you might come back and find \$108 in your account on December 31st. This is often called the compound annualized growth rate (CAGR)–meaning that if you have \$100 one year, earn 8%, you have 108, and then earn 8% on that, and so on.

The second thing to look at is the risk. What can you lose? The simplest answer to this is “the maximum drawdown”. If this sounds complicated, it simply means “the biggest loss”. So, if you had \$100 one month, \$120 next month, and \$90 the month after that, your maximum drawdown (that is, your maximum loss) would be 1 – 90/120 = 25%.

When you put the reward and risk together, you can create a ratio, to see how your rewards and risks line up. This is called a Calmar ratio, and you get it by dividing your CAGR by your maximum drawdown. The Calmar Ratio is a ratio that I interpret as “for every dollar you lose in your investment’s worst performance, how many dollars can you make back in a year?” For my own investments, I prefer this number to be at least 1, and know of a strategy for which that number is above 2 since 2011, or higher than 3 if simulated back to 2008.

Most stocks don’t even have a Calmar ratio of 1, which means that on average, an investment makes more than it can possibly lose in a year. Even Amazon, the company whose stock made Jeff Bezos now the richest man in the world, only has a Calmar Ratio of less than 2/5, with a maximum loss of more than 90% in the dot-com crash. The S&P 500, again, “the stock market”, since 1993, has a Calmar Ratio of around 1/6. That is, the worst losses can take *years* to make back.

A lot of wealth advisers like to say that they recommend a large holding of stocks for young people. In my opinion, whether you’re young or old, losing half of everything hurts, and there are much better ways to make money than to simply buy and hold a collection of stocks.

****

For those with coding skills, one way to gauge just how good or bad an investment is, is this:

An investment has a history–that is, in January, it made 3%, in February, it lost 2%, in March, it made 5%, and so on. By shuffling that history around, so that say, January loses 2%, February makes 5%, and March makes 3%, you can create an alternate history of the investment. It will start and end in the same place, but the journey will be different. For investments that have existed for a few years, it is possible to create many different histories, and compare the Calmar ratio of the original investment to its shuffled “alternate histories”. Ideally, you want the investment to be ranked among the highest possible ways to have made the money it did.

To put it simply: would you rather fall one inch a thousand times, or fall a thousand inches once? Well, the first one is no different than jumping rope. The second one will kill you.

Here is some code I wrote in R (if you don’t code in R, don’t worry) to see just how the S&P 500 (the stock market) did compared to how it could have done.

```require(downloader)
require(quantmod)
require(PerformanceAnalytics)
require(TTR)
require(Quandl)
require(data.table)

SPY <- Quandl("EOD/SPY", start_date="1990-01-01", type = "xts")

spySims <- list()
set.seed(123)
for(i in 1:999) {
simulatedSpy <- xts(sample(coredata(SPYrets), size = length(SPYrets), replace = FALSE), order.by=index(SPYrets))
colnames(simulatedSpy) <- paste("sampleSPY", i, sep="_")
spySims[[i]] <- simulatedSpy
}
spySims <- do.call(cbind, spySims)
spySims <- cbind(spySims, SPYrets)
colnames(spySims)[1000] <- "Original SPY"

dailyReturnCAGR <- function(rets) {
return(prod(1+rets)^(252/length(rets))-1)
}

rets <- sapply(spySims, dailyReturnCAGR)
drawdowns <- maxDrawdown(spySims)
calmars <- rets/drawdowns
ranks <- rank(calmars)
plot(density(as.numeric(calmars)), main = 'Calmars of reshuffled SPY, realized reality in red')
abline(v=as.numeric(calmars[1000]), col = 'red')
```

This is the resulting plot:

That red line is the actual performance of the S&P 500 compared to what could have been. And of the 1000 different simulations, only 91 did worse than what happened in reality.

This means that the stock market isn’t a particularly good investment, and that you can do much better using tactical asset allocation strategies.

****

One site I’m affiliated with, is AllocateSmartly. It is a cheap investment subscription service (\$30 a month) that compiles a collection of asset allocation strategies that perform better than many wealth advisers. When you combine some of those strategies, the performance is better still. To put it into perspective, one model strategy I’ve come up with has this performance:

In this case, the compound annualized growth rate is nearly double that of the maximum loss. For those interested in something a bit more aggressive, this strategy ensemble uses some fairly conservative strategies in its approach.

****

In conclusion, when considering how to invest your money, keep in mind both the reward, and the risk. One very simple and important way to understand risk is how much an investment can possibly lose, from its highest, to its lowest value following that peak. When you combine the reward and the risk, you can get a ratio that tells you about how much you can stand to make for every dollar lost in an investment’s worst performance.

NOTE: I am interested in networking opportunities, projects, and full-time positions related to my skill set. If you are looking to collaborate, please contact me on my LinkedIn here.

An Out of Sample Update on DDN’s Volatility Momentum Trading Strategy and Beta Convexity

The first part of this post is a quick update on Tony Cooper’s of Double Digit Numerics’s volatility ETN momentum strategy from the volatility made simple blog (which has stopped updating as of a year and a half ago). The second part will cover Dr. Jonathan Kinlay’s Beta Convexity concept.

So, now that I have the ability to generate a term structure and constant expiry contracts, I decided to revisit some of the strategies on Volatility Made Simple and see if any of them are any good (long story short: all of the publicly detailed ones aren’t so hot besides mine–they either have a massive drawdown in-sample around the time of the crisis, or a massive drawdown out-of-sample).

Why this strategy? Because it seemed different from most of the usual term structure ratio trades (of which mine is an example), so I thought I’d check out how it did since its first publishing date, and because it’s rather easy to understand.

Here’s the strategy:

Take XIV, VXX, ZIV, VXZ, and SHY (this last one as the “risk free” asset), and at the close, invest in whichever has had the highest 83 day momentum (this was the result of optimization done on volatilityMadeSimple).

Here’s the code to do this in R, using the Quandl EOD database. There are two variants tested–observe the close, buy the close (AKA magical thinking), and observe the close, buy tomorrow’s close.

```require(quantmod)
require(PerformanceAnalytics)
require(TTR)
require(Quandl)

Quandl.api_key("yourKeyHere")

symbols <- c("XIV", "VXX", "ZIV", "VXZ", "SHY")

prices <- list()
for(i in 1:length(symbols)) {
price <- Quandl(paste0("EOD/", symbols[i]), start_date="1990-12-31", type = "xts")\$Adj_Close
colnames(price) <- symbols[i]
prices[[i]] <- price
}
prices <- na.omit(do.call(cbind, prices))
returns <- na.omit(Return.calculate(prices))

# find highest asset, assign column names
topAsset <- function(row, assetNames) {
out <- row==max(row, na.rm = TRUE)
names(out) <- assetNames
out <- data.frame(out)
return(out)
}

# compute momentum
momentums <- na.omit(xts(apply(prices, 2, ROC, n = 83), order.by=index(prices)))

# find highest asset each day, turn it into an xts
highestMom <- apply(momentums, 1, topAsset, assetNames = colnames(momentums))
highestMom <- xts(t(do.call(cbind, highestMom)), order.by=index(momentums))

# observe today's close, buy tomorrow's close
buyTomorrow <- na.omit(xts(rowSums(returns * lag(highestMom, 2)), order.by=index(highestMom)))

# observe today's close, buy today's close (aka magic thinking)
magicThinking <- na.omit(xts(rowSums(returns * lag(highestMom)), order.by=index(highestMom)))

# results
charts.PerformanceSummary(out['2014-04-11::'], legend.loc = 'top')
rbind(table.AnnualizedReturns(out['2014-04-11::']), maxDrawdown(out['2014-04-11::']))
```

Pretty simple.

Here are the results.

```> rbind(table.AnnualizedReturns(out['2014-04-11::']), maxDrawdown(out['2014-04-11::']))
Annualized Return          -0.0320000       0.0378000
Annualized Std Dev          0.5853000       0.5854000
Annualized Sharpe (Rf=0%)  -0.0547000       0.0646000
Worst Drawdown              0.8166912       0.7761655
```

Looks like this strategy didn’t pan out too well. Just a daily reminder that if you’re using fine grid-search to select a particularly good parameter (EG n = 83 days? Maybe 4 21-day trading months, but even that would have been n = 82), you’re asking for a visit from, in the words of Mr. Tony Cooper, a visit from the grim reaper.

****

Moving onto another topic, whenever Dr. Jonathan Kinlay posts something that I think I can replicate that I’d be very wise to do so, as he is a very skilled and experienced practitioner (and also includes me on his blogroll).

A topic that Dr. Kinlay covered is the idea of beta convexity–namely, that an asset’s beta to a benchmark may be different when the benchmark is up as compared to when it’s down. Essentially, it’s the idea that we want to weed out firms that are what I’d deem as “losers in disguise”–I.E. those that act fine when times are good (which is when we really don’t care about diversification, since everything is going up anyway), but do nothing during bad times.

The beta convexity is calculated quite simply: it’s the beta of an asset to a benchmark when the benchmark has a positive return, minus the beta of an asset to a benchmark when the benchmark has a negative return, then squaring the difference. That is, (beta_bench_positive – beta_bench_negative) ^ 2.

Here’s some R code to demonstrate this, using IBM vs. the S&P 500 since 1995.

```ibm <- Quandl("EOD/IBM", start_date="1995-01-01", type = "xts")

spy <- Quandl("EOD/SPY", start_date="1995-01-01", type = "xts")

rets <- na.omit(cbind(ibmRets, spyRets))
colnames(rets) <- c("IBM", "SPY")

betaConvexity <- function(Ra, Rb) {
positiveBench <- Rb[Rb > 0]
assetPositiveBench <- Ra[index(positiveBench)]
positiveBeta <- CAPM.beta(Ra = assetPositiveBench, Rb = positiveBench)

negativeBench <- Rb[Rb < 0]
assetNegativeBench <- Ra[index(negativeBench)]
negativeBeta <- CAPM.beta(Ra = assetNegativeBench, Rb = negativeBench)

out <- (positiveBeta - negativeBeta) ^ 2
return(out)
}

betaConvexity(rets\$IBM, rets\$SPY)
```

For the result:

```> betaConvexity(rets\$IBM, rets\$SPY)
[1] 0.004136034
```