The average daily trading volume in agency MBS climbed to $201.4 billion in February, the best reading in nine months and a sign that investors will still flock to government-backed products in times of uncertainty, especially extreme uncertainty. Late this week, market watchers expressed their concerns about the terrorist bombings in Belgium as well as continued worries about China’s slowing economy and sagging oil prices. In short order, they piled into MBS issued by Fannie Mae, Freddie Mac and Ginnie Mae. Barry Habib, who runs MBS Highway, a rate-lock service, told...