S&P 500 index up a year after every midterm since 1990, averaging 16.9%

The S&P 500 — an index of 500 large U.S. companies — closed higher 12 months after Election Day in all nine midterms since 1990, YCharts data show. The average total return, including dividends, was 16.9%. That history is not a forecast: nine cases is a small sample for savers judging risk.