Dow Jones Takes Deepest Plunge Since September The Dow Jones Industrial Average experienced a three-digit drop on Monday, its biggest one-day drop since September, as other stocks fell dramatically at the close of the market. The S&P 500 fell by 23 points and Nasdaq fell by 61 points, marking their biggest one-day declines since November, CNBC reports. The network linked the decline to a Monday speech delivered by Atlanta Federal Reserve President Dennis Lockhart who said he supported further tapering of bond purchases. The Wall Street Journal linked the decline to last week's jobs report and the quarterly earnings reports coming this week.