I am starting to use longer timeframes, such as one year. I consider this a long-term experiment and will continue my research. Based on the improvement in returns I have seen from GPT-3.5 to GPT-4, my hypothesis is that it will continue to outperform $SPY as the models become smarter. For reference, GPT-4's return was approximately 156.86% better than GPT-3.5's return. GPT-3.5 didn't actually beat $SPY.