Stocks took a big step back Tuesday, erasing all of Monday’s big rebound and raising new questions about the market’s rally attempt. The Nasdaq slumped 1.4%, marking its biggest loss in more than a week. Google (GOOGL) dropped 2% and neared its 200-day line. Apple (AAPL) lost 1%. New issue Twitter (TWTR) plunged to a record low as its lockup period expired.