Jas-105 posts: What do you think has made Turtle System One lose its profitability , how have the markets changed ? Is it just more short-term volatility or "noise" or has it been an increase in trading systems that pick-off longer-term systems , or something else ?
Anthony Garner has a nice article in the Feb 2010 issue of Active Trader magazine which discusses this: "Tuning up the Turtle System". He suggests a few modifications to the system, which result in a much improved equity curve post-1993. His modifications include
- Widening the Donchian (breakout) channels
- Widening the initial stop
- Enlarging the portfolio
- (To go with the bigger portfolio): install Max Sector Risk and Max Portfolio Risk limits
- Switching from scaling-in ("pyramiding") to scaling-out ("profit target exits")
- Adding a Very-Long-Term-trend filter which only permits trades in the direction of the VLT trend
There have been lots of discussions here about "what happened to the Turtle System's performance" and/or "have the markets changed". Here are a few of the threads to get you started. You can find many more by performing a little Google-Fu (in Advanced Search, fill in the bottom box "Search within a site or domain" with tradingblox.com)
viewtopic.php?t=5428
viewtopic.php?t=3637
viewtopic.php?t=3779
viewtopic.php?p=40810