When home prices declined in the latter half of 2007 and the secondary mortgage market collapsed, IndyMac was forced to hold $10.7 billion of loans it could not sell in the secondary market. Its reduced liquidity was further exacerbated in late June 2008 when account holders withdrew $1.55 billion or about 7.5% of IndyMac's deposits. This “run” on the thrift followed the public release of a letter from Senator Charles Schumer to the FDIC and OTS. The letter outlined the Senator’s concerns with IndyMac. While the run was a contributing factor in the timing of IndyMac’s demise, the underlying cause of the failure was the unsafe and unsound manner in which the thrift was operated.

What was the value of loans IndyMac was forced to hold when the secondary mortgage market collapsed in late 2007?