Stocks post best September in 71 years

U.S. stocks fizzled Thursday, but that didn't stop the market from logging its best September in decades.

Dow Jones industrial average (INDU) slipped 47 points, or 0.4%, after soaring more than 100 points at the start of trading. The S&P 500 (SPX) fell 4 points, or 0.3%, and the Nasdaq (COMP) ticked down 8 points, or 0.3%.

Economic jitters have kept stocks from breaking out of a narrow range this week. And while upbeat readings on employment and economic growth helped spark an early rally Thursday, gains subsided as worries about the euro zone bubbled up.

Despite the stomach churning month, stocks ended September on a high note. The Dow jumped 7.7%, the biggest September gain in 71 years. The S&P also posted the biggest gain since 1939, rising 8.7% in the month, while the Nasdaq climbed 12%.