This morning, the central bank announced further measures to address the liquidity problems facing financial institutions caught up in the mortgage mess. The Fed said it will lend up to $200 billion to securities dealers for periods as long as four weeks, rather than overnight, which is the current policy.

Stocks rallied on the Fed move. At 11:30 a.m. ET, the Dow Jones Industrial Average was up 216 points to 11,956 after losing 153 points on Monday. As of Monday’s close, the Dow had lost 546 points, or 4.3%, this month and had shed 11.5% for the year.

This morning, the Nasdaq Composite Index had gained 44 points to 2,214, and the Standard & Poor’s 500 Index had added 22 points to 1,296.