Trend-following is not such a good model. It’s simply eroded. Things change and being able to adjust is what made Mr. Simons so successful. “Statistic predictor signals erode over the next several years； it can be five years or 10 years. You have to keep coming up with new things because the market is against us. If you don’t keep getting better， you’re going to do worse.
If you have an apple and I have an apple, and we exchange apples, we both still only have one apple. But if you have an idea and I have an idea, and we exchange ideas, we each now have two ideas.
