The Dow Jones Industrial Average fell nearly 1,600 points at its lows on Monday, after a period of selling accelerated sharply heading into the close of the session. Amplifying the slump was computer-programmed trade set to dump shares at certain levels. According to traders, the Dow DJIA, -0.87% was set to trigger trades once it fell below 25,000 and 24,000, for example, and 2,700 for the S&P 500 SPX, -1.11% . The S&P 500 finished the session off 113 points, or 3.9% at 2,648, the Nasdaq Composite Index COMP, -1.07% ended down 273 points, or 3.8%, at 6.967. The Dow, meanwhile, shed as much as 1,597 points at its low, and closed out the session 1,175 points, or 4.6%, down at 24,345.