I wonder if it would make sense for us to delay ingestion of prices by a few days on the volatility indices since they have these large spikes that quickly reverse.
For example, if I were short 5 contracts, then the Vix spikes by 10% on day n, my system does not react since the latest price it has is from three days ago. Then the Vix completely reverses its spike on day n+1 or n+2 (this seems to happen nearly every time it spikes). I would gain back whatever I lost on day n, since I am still short 5 contracts, since my system hasn't reacted to the spike. Then, on day n+3, my system reacts to the spike by reducing exposure, but at that point we are back to normal volatility. Is this type of system-tinkering a no-no?
Good points, GAT. However, I believe that your system does not allow a positive forecast on the volatility indices. Is this correct? If so, could one argue that that represents overfitting based on past data, since you allow positive forecasts on all other instruments?This is a classic path to overfitting... which I call "fighting the last battle". And don't worry, it's endemic to both retail and institutional investors, as the latter are always under pressure from investors to "improve" their system and make it more "resiliant" to whatever went wrong last week..
What is the systematic way to approach this? You'd need to fit some kind of non linear response to volatility changes. You'd need to fit this out of sample, and on a market specific (or perhaps across asset classes) basis, since you think this effect only occurs on the volatility indices. That means a lot of parameters. It's highly unlikely this will be a successful enterprise. At best you might get a small, non statistically significant, improvement in performance - in exchange for a huge of complexity.
But if you want to pursue this, be my guest. But I strongly advocate that you don't just introduce a discretionary fiddle into your system in the way you suggest.
GAT
Good points, GAT. However, I believe that your system does not allow a positive forecast on the volatility indices. Is this correct? If so, could one argue that that represents overfitting based on past data, since you allow positive forecasts on all other instruments?
I see, so you combine this fixed forecast of -10, with the variable forecasts you get from EWMAC, carry, and any other rules you have set up, to result in a short bias to volatility indices?
Imho you're being too gentle there GAT. N@D has taken a serious risk with his/her trading account and managed to get away with a minor injury by pure good fortune. The initial suggested remedy (a kind of over-fitting to recent benign markets) was deeply inappropriate and suggestive of almost no understanding of what he/she is doing as well. N@D needs to take a good hard look at their approach and risk-management before it's too late.