Commercial banks solidified their status as the biggest investor class in the MBS market over the second half of 2011, according to a new analysis by Inside MBS & ABS. Banks increased their holdings of residential MBS by some 5.7 percent over the final six months of last year – a period during which the MBS market itself was shrinking by 2.3 percent. That raised the commercial bank share of the MBS market to 21.1 percent. Savings institutions and credit unions, both significantly smaller groups than commercial banks, also boosted their MBS holdings in 2011. In fact, the...(Includes one data chart)