Stocks delivered a weak follow-up to Thursday’s resumed uptrend as signs of institutional selling reappeared. The Nasdaq fell 0.3% while the S&P 500 slipped less than 0.1%. Small caps took the day’s hardest hit. The S&P 600 skidded 1.1%. The IBD 50 fell 0.4%. Volume rose across the board, partly because of quadruple witching expirations and the IPO of Alibaba (BABA).