UPDATE 1-Stock funds attract $2.9 bln in latest week - Lipper

(New throughout, adds details on negative four-week moving averages for investment grade and junk bond mutual funds) By Trevor Hunnicutt NEW YORK, Nov 27 (Reuters) - Investors in exchange-traded funds added nearly $7.7 billion to U.S.-based stock funds during the week ended Nov. 25, data from Thomson Reuters' Lipper service showed Friday, moderating a wave of withdrawals by mutual-fund investors from risky assets. Overall, U.S.-based stock mutual funds and ETFs attracted $2.9 bill