S&P 500 ended 2025 up 16%, but fell 1% in the final five trading days. An LPL Financial analysis links weak year-end performance to lower returns in the following year. Historical trends do not guarantee future results, and 2026 began with S&P 500 gains. While the S&P 500 closed out 2025 up 16%, the index ended the year on the wrong foot, posting negative returns during the market's final five trading days. According to a report from LPL Financial, that could mean stocks are in for a lackluster y ...