By Al Yoon Of DOW JONES NEWSWIRES NEW YORK -(Dow Jones)- Banks, hedge funds and other financial institutions are "raining assets" on the markets as they reduce risk, countering the Federal Reserve's efforts to stimulate the economy, the head of a mortgage bond investment firm said Wednesday. Annaly Capital Management (NLY) Chief Executive Michael Farrell said the New York-based real estate investment trust has reduced its debt and amassed a $3.5 billion "war chest" to exploit falling asset prices as competitors also race to raise cash by selling assets. Speaking on a conference call, Farrell suggested that investors extrapolate the unwinding of failed firm MF Global over companies or hedge funds that will need to reduce risk on their balance sheets ahead of stiffer regulation. Selling is coming from domestic and foreign sources for a variety of reasons, including avoiding currency risk and avoiding the margin-damping effects that faster home-loan refinancing will have on mortgage-backed securities, he added. "It's raining assets," Farrell said. "And you want to be (as) bulletproof as you can be during that period." The selling is so deep that higher-yield spreads are likely "here for a while," which is hurting the Fed's ability to affect the market by keeping interest rates low, he said. Later Wednesday, Fed Chairman Ben Bernanke said the Fed stood ready to provide additional support to the weak U.S. housing market. More purchases of mortgage-backed securities were a viable option, and would be considered if conditions were appropriate, he said. Annaly on Tuesday reported a loss of $922 million last quarter. Excluding unrealized gains or losses on derivatives, net income was $623 million. -By Al Yoon, Dow Jones Newswires; 212-416-3216; albert.yoon@dowjones.com