(MONEY Magazine) – Presidential-election years tend to be up years for stocks--the S&P 500 rose in 11 of 13 such years since 1952, the Stock Trader's Almanac shows. Average gain: 9%. The year's last eight months tend to be stronger: In election years since 1952, the average rise from May through December was 7.2% vs. 2% for January through April. One possible reason: less electoral uncertainty. "The conventions are wrapped up in the summer, and there's a clearer battle at hand," says Jeffrey Hirsch, the almanac's editor. --DONNA ROSATO

Year's President Year change elected

1960 -3.0 John F. Kennedy 1964 13.0 Lyndon Johnson 1968 7.7 Richard Nixon 1972 15.6 Richard Nixon 1976 19.1 Jimmy Carter 1980 25.8 Ronald Reagan 1984 1.4 Ronald Reagan 1988 12.4 George H. W. Bush 1992 4.5 Bill Clinton 1996 20.3 Bill Clinton 2000 -10.1 George W. Bush

Source: StockTradersAlmanac.com.