By CHRISTINA REXRODENEW YORK (AP) â¿¿ For the second time in less than a month, the stock market marched past another milepost on its long, turbulent journey back from the Great Recession, toppling another record left over from the days before government bailouts and failing investment banks. The Standard & Poor's 500 closed at a new high Thursday, three weeks after another popular market gauge, the Dow Jones industrial average, obliterated its own closing record. The S&P capped its best quarter in a year, rising 10 percent, and the Dow had its best first quarter in 15 years, climbing 11 percent. The numbers offer more evidence that investors believe the economy is on the mend, said Sam Stovall, chief equity strategist at S&P Capital IQ. "The low-flying recovery is gaining altitude," Stovall said, citing a truism among investors that rising stock prices come first, then the economy catches up. Thursday's performance was driven by encouraging economic data. Companies are making record profits quarter after quarter. They're hiring in greater numbers, and the housing market is finally recovering. The economy has expanded for 14 quarters in a row. The Fed has helped, too. By keeping interest rates near record lows, the central bank has encouraged people to move money out of savings accounts that pay next to nothing and into stocks and other investments. Investors warned clients not to get overly excited. "Getting back to where we were is an important step," said Howard Silverblatt, senior index analyst at S&P Dow Jones Indices. But he cautioned in a note to investors: "Markets are volatile, and if you are a long-term investor you should expect declines." On Thursday, the S&P 500 rose 6.34 points, or 0.41 percent, to 1,569.19, beating by four points its previous record of 1,565.15 set on Oct. 9, 2007. The index is still shy of its all-time trading high of 1,576.09.