Stocks sold off and closed near session lows Thursday as the European Central Bank’s stimulus action and Fed chief Janet Yellen’s remarks weighed on the market. The Nasdaq plunged 1.7%, and the S&P 500 and Dow Jones industrial average each tumbled 1.4%. Volume swelled across the board, according to preliminary data. Losers swamped winners by more than a 4-to-1 margin on the NYSE and by 3-to-1 on the Nasdaq.