After the S&P 500 experienced three consecutive years of above-average returns in 2023, 2024 and 2025, and with traditional valuation metrics looking expensive, the question on many investors’ minds is: “should I sell?” The data says not so fast – the 17.9% return in 2025 ranked in only the 54th percentile over the last 100 years. Don’t sell because markets feel too good. Sell because something in your plan has actually changed.