Mortgage-backed securities opened much higher this morning on news of the government takeover of Fannie Mae and Freddie Mac, resulting in the largest one-day drop in mortgage rates this year. While a conservator will have control over the two mortgage giants, day-to-day operations are expected to continue uninterrupted and with few changes. Stocks rallied in the US and abroad on the news. The dollar moved to its highest levels against the euro since last year. Oil continued its slide, reaching $105 pb.