Mortgage meltdown boosts One of the oddest side effects of the credit crunch, which most recently brought about the nationalization of mortgage giants Fannie Mae and Freddie Mac: shares are soaring . Fannie and Freddie's fall hasn't boosted Salesforce's business. But Freddie Mac has been taken off the S&P 500 stock index, which made room for Index-tracking funds which are required to match its makeup have been buying as a result.