(Reuters) - U.S. -based stock funds in the week ended Wednesday shed $12.4 billion, the biggest outflow since September, according to Lipper. U.S. taxable bond funds attracted $12 billion, which was biggest weekly inflow since October, while money market funds shed $12.7 billion, marking the largest outflow in seven weeks, Lipper data showed on Thursday. U.S. municipal bond funds attracted $1.6 billion, the 13th straight weekly inflow.