Your Trading System Needs Internal Controls

I've said this before, but it's worth repeating - especially after reading about the rise and fall of Soul Trader's Grail forex system, which I always regarded as one of the most advanced automated systems around. Reading his explanation of why this system finally had to be shut down really brought home to me the need for rigorous internal controls on your trading system.

By internal controls I mean the type of tracking algorithms that watch over your trading performance and intervene to shut it down when performance begins to dip. Or to paraphrase Soul Trader, "How to identify when the market conditions cause the system to fail, and what to do when it's failed."

String of losses over X% of trading capital? Click: the system goes off until performance improves. Recent trading odds dip below Y%? Sorry, you're out of the market until things perk up - and if they don't perk up, you'll just have to be patient and appreciate the fact that at least your funds are safe. Preserving your capital in adverse conditions is pretty boring, but it's one of the most important single factors in trading success.

The only reason I'm still trading, and have even bothered to return to trading after a recent hiatus, is because of these built-in trading restrictions. I think of them as a firewall between me and the worst the market can dish out. They're not perfect, and they certainly don't prevent all drawdowns all the time, but they're a lot better than nothing at all. In fact, given the choice I'd much rather trade with no stop-losses and strong internal controls than vice versa.

Disclaimer: check back in a few weeks and see if I've abandoned my trading controls because they failed completely in unexpected market conditions.