Business news for Sat, 22 Dec 2007 & with words major+market. 2 news.

Mortgage losses may affect some firms' ability to pay claims. The financial troubles of major bond insurers are rattling the municipal bond market, where about half the bonds issued in recent years have carried private insurance -- including in California.

STOCKS jumped yesterday following a better-than-expected rise in profits at Research in Motion Ltd. and on word that Merrill Lynch may have lined up a big cash infusion from a Singapore fund. The Dow Jones industrial average capped a volatile week with a gain of more than 200 points and, along with the other major indexes, posted an increase of more than 1.5 percent. The developments seemed to allay investor fears that economic growth would succumb to tightness in the credit markets. Adding to the measure of relief some investors felt, the Federal Reserve said it would continue with its special biweekly auctions for banks as long as necessary to relieve strains in the short-term debt market. The announcements came as the New York Stock Exchange set a record for volume in the first half hour and hour of trading during what is known as "quadruple witching." It marks the simultaneous expiration of contracts for stock index futures, stock index options, stock options