While the players and regulators were struggling to get investors to commit capital to the major banks to avoid a meltdown, Warren Buffet was called upon several times.  He consistently turned them down because the assets were too complicated to understand, and he did not trust most players on Wall Street. But he was finally offered a deal he could not refuse.

Warren was offered $5 billion worth of preferred stock in Goldman Sachs, the Cadillac of the Wall Street firms, with a 10% yield ($500 million annually), convertible into Goldman stock at $115 a share, 8% below the then current price.

That is why cash is king

Info from Too Big To Fail by Andrew Ross Sorkin