Saturday, October 26, 2019

Using volatility contraction to increase your profits

Often you see people talking about a winning trade, and how far in percentage terms price moved in their favour after entry.

But on its own, this doesn't tell you anything - to me, it is a worthless metric when evaluating performance.

As a trader, I'm far more interested in the size of the profit (or loss) generated when expressed in terms of R.

As an example, lets take two hypothetical stocks - Stock A moves 500% in your favour after entry, while Stock B advances 'only' 100%.

On the face of it, you may think that Stock A was the better trade. But lets add some additional information - the type which people who brag about big percentage moves typically don't give you:

Stock A gave an entry signal when price hit $20. The 500% move meant that the trade was closed when price reached $120.

What you didn't know is that the initial stop was placed at $10, being $10 from the entry price. Therefore, each unit of R (being the initial risk on the trade) equates to a price movement of $10. 

In this example, price moved $100 in your favour post-entry, meaning that the profit on the trade equated to +10R (the $100 price movement divided by the value of 1 unit of R).

Now lets take Stock B.

In this case, an entry was also triggered at $20, and the 100% price move meant that the trade was closed when the stock was at $40.

The crucial difference here is that the initial stop was placed at $19, a distance of only $1. This means that each unit of R also equated to $1.

As a result of price moving $20 in your favour, trading stock B yielded a profit equivalent to +20R.

Therefore, trading Stock B meant you would have made twice the profit compared to trading Stock A.

Now, as a trader, which would you rather have - the bigger moving stock (in percentage terms), or the trade which yielded the bigger profit?

Secondly, how can you identify more setups like Stock B?

The potential answer comes in looking at how your initial stop distance is calculated, and how you interpret volatility.

Some traders choose to adopt a fixed percentage or price distance as an initial stop, regardless of the level of volatility in the stock or instrument they are looking to trade.

Others however adopt a volatility-based position sizing model, such as using a multiple of Average True Range.

When adopting this model, you are effectively looking for setups where volatility has contracted and / or the ATR reading is at a low level compared to previous weeks, months, or even years!

These types of setups have the benefit of allowing the use of a smaller initial stop distance.

As a result, you are able to have a larger position size, while keeping to the same percentage of equity at risk on the trade.

Should price then move in your favour after entry, it has to move a smaller distance to generate each 'unit' of profit when measured in R.

The examples and explanations above should make it clear it is not how far price moves after entry which solely determines the size of the profit.

In this post I talked about how some of the famous trend followers also identified and used volatility.

Finally, a word of warning.

Wherever there is potential reward, there is also risk. There is an ever-present danger that, by using a very tight stop and a larger position size, a sudden price move or overnight gap can result in an actual loss far greater than the amount you original risked on the trade.

These can be caused by earnings releases, or by unexpected government or central bank announcements - the most extreme example in recent years being the Swiss Franc price movement in early 2015.

Therefore, ensure that you consider and factor in the unexpected when formulating your rules both in terms of your initial stop distance and your overall percentage of equity on each trade.


  1. If you've tested your system and then incorporate volatility based position sizing- you are reducing the sample size of you back tested system. You would have to prove to yourself that entering on lower volatility entries would have an equal and/ or better result of expectancy of having a winning trade. What you are doing is using a volatility contraction as a filter- which may or may not make the system more profitable!

    1. Given that I predominantly trade stocks and am not limited to trading a small 'basket' of selected names, I have a potential universe of thousands to look at, so the volatility contraction is a good way of filtering potential setups. Also, given that trend followers like Parker and Hite have stated the benefits of tracking volatility, who am I to argue? I'm not going to waste my time re-inventing the wheel.

  2. Not to belabor the point- but although Jerry mentions tracking volatility- I've never heard him use that as part of a criteria for entries or exits, but yes for position sizing and stop values (Hite I'm not sure).

    Secondly- for increased profits the trend would still have to breakout in more multiples of "R" then
    with an initial higher "R" on entry.

    I also use volatility (It seems the only thing that does somewhat revert to the mean)- but for the increased position size achieved with a lower "R" on entry - your stop (if based on a multiple "R") would be closer- which might actually result in more whipsaws, and hence a lower win rate.

    PS- I love the site! Good work.

  3. “It seems to be increasingly true that volatility screens are a good idea; the trades with the lowest volatility for trend-following are best.” ~ Richard Dennis

    1. Richard has had great success and also big blow ups ...... For me and my system, volatility based position sizing doesn't work, you end up having a larger position size when the potential for a winning trade is lower.

      "Finally, a word of warning.
      Wherever there is potential reward, there is also risk. There is an ever-present danger that, by using a very tight stop and a larger position size, a sudden price move or overnight gap can result in an actual loss far greater than the amount you original risked on the trade."

    2. Excerpted from an article originally published in the April 2005 issue of Technical Analysis of STOCKS & COMMODITIES magazine.
      Richard also points out that the market changes- that's from 2005!