IndyMacs annual report has the following Sensitivity to Interest Rates section: We estimate the net sensitivity of the value of our financial instruments to movements in interest rates using duration gap analysis. At December 31, 2007, the net duration gap for our mortgage banking and thrift segments was negative 16.9 months.

(a) Explain what this means. How might this be related to why IndyMac is bankrupt?

(b) If this is bad, what could IndyMac have done to manage the risks associated with this?