Facebook Valued at $50 BILLION

Goldman Sachs is investing $450 million in Facebook at a $50 billion valuation, the New York Times' Dealbook reports.  Goldman's investment comes alongside a new $50 million investment from existing Facebook investor DST, the Russian investment firm that has also invested in Groupon and Zynga. And Goldman has the right to sell up to $75 million of its stake to DST, the NYT's Andrew Ross Sorkin and Evelyn Rusli report.  Also as part of the deal, Goldman will help raise up to another $1.5 billion for Facebook at that $50 billion valuation, according to the NYT…..