Originally posted by acrary
Yes, I posted some stuff over there.
The difference between trading off market character and an edge is the difference between night and day. Market character refers to the past history of the market. Assumptions are made that the past will be similar to the future. Traders fool themselves into believing that if I test with enough past history and look for robustness, it'll work just fine. People that trade off character are trading off of historical tendencies. This is like trying to drive a car with the windshield blacked out and driving by looking out the back window. Imagine a car on a road in the desert. Most of the time it's straight with a few turns. By watching the side of the road and making constant adjustments they could probably drive at 20-30 mph without a problem. Now the market character changes and they're in the mountains. Hairpin turns, windy roads, dirt roads, etc. The methods used in the desert no longer work. The driver would have to slow to 1/2 the speed to have a chance of survival. If they kept looking out the back and drove as fast as in the desert, they'd be off a cliff in no time. No wonder people say psychology is important. If you're trading like this, you're always worrying about the market changing.
Edge trading is based on finding non-random conditions in the market and using them to trade. Unfortunately, edges are not always perfectly defined, so we may not get 100% perfect trades. This is like having a small spot open in the windshield from which to see through. If the edge is small, maybe we can only see 50 feet in front of the car. This is enough to allow us to go much faster in the desert and drive with confidence in the mountains. To the trader with an edge, accounts compound much faster and with lower drawdowns than market character. The size of the edge can be measured. If you're interested in how, check the edge thread under the psychology forum.
I have a edge in the SP markets that I found using weekly data. All the trades are done by buying/selling on Monday at the open and exiting on Friday on the close. No stops! You would expect any method like this to have had trouble in the past two years with the long side trades. Afterall, we've been in a downtrend. Here's the long side trade summary for 2001 and 2002 (up to the present).