American International Group Inc's (NYSE:AIG) investment strategy is to embrace distressed mortgages which are trading at discounted prices and offer attractive cash flows, in lieu of equities which are more impacted by shifts in the equity markets. While AIG's mortgage portfolio got them in a considerable amount of trouble during the "Great Recession" the primary problems that the company incurred was due to a liquidity squeeze. Their financial products division faced 10's of billions of dollars in collateral demands when credit default swaps that the division sold fell in price. Fortunately the company has liquidated or exited much of that business, so while the mortgages that they are buying aren't nearly as liquid as buying a stock on an exchange for instance, the insurance company operates much more as a traditional insurance company now, therefore the company has the ability to hold on to the mortgages for their duration. Therefore the value of future cash flows will be much more important to the company than short term mark to market swings in the price of the securities.
Disclosure: I am long AIG.