How do you expect anyone to answer your questions? You provide next to no information. Derive the source of your alpha and investigate why it's not there during the period in question. For more we need more information.
Hello guys, I've elaborated some trading strategies for different stocks, and I have backtested them over the last 11 years. The results are very compelling. The problem is that when I test them over another period (1997-2007), the results get materially different and worse. What do you think about this problem ? What do you think would be the best way for proceeding ? Thank you for any advice.
very frustrating