Quote Originally Posted by Billy View Post
Aly,
I've heard and read for years the same 2/3 and 1/3 proportion.
But it all really depends on the timeframe you're looking at. I know traders in this forum who deem a 1-hour trend an eternity and others who are only looking at monthly trends!
For the robot, ST is a 3-day horizon and LT is a 10-day horizon. It seems to be the best timeframe compromises for optimizing what we are trying to achieve: consistent compounded (very) long term risk-adjusted returns.
I suggest that you explore the Market Sci blog archives for their posts about research on mean-reversion and trend-following markets. They were big promoters of mean-reversion strategies until they discovered that for the last few years a shift clearly happened in favor of trend-following strategies. They explain why they think this phenomenon can only accelerate in the years ahead.
I think also that modern algo and HFT trading can only precipitate more trend-following.
Billy
Thanks for the tips, Billy.

Will take a look at those archives and ponder on your thoughts as well.