Summary: Stocks tanked on the last trading day of the month to make this January the largest monthly drop since last January. The selling accelerated in the final hour of trading sending the Dow Jones Industrial to drop 251 points. Oil prices soared, catching traders off guard. Crude gained more than 8% to settle up by $3.71 a barrel. The surge came after Baker Hughes (BHI) said the number of U.S. rigs in operation fell by another 94. That's the biggest one week drop since 1987. Shake Shack (SHAK) had a great first day of trading with shares up 118% on its debut. Google (GOOG) gained in the session as well despite missing Wall Street's revenue expectations. And Visa (V) was the only blue chip to close in the green ending 2.79% higher.
