Buried Lede

From Fortune, March 17, 2008, "The Man Who Must Keep Goldman Growing", by Bethany McLean (pp. 131 - 140):

"Goldman spotted the problem early because it is fanatical about pricing its holdings at their current market value - even at times forcing traders to sell part of a position to establish a price." (pg. 140)

Goldman Sachs was the only one of the major independent investment banking firms to make money from the subprime meltdown. The other banks have posted billions of dollars in losses because their subprime holdings have lost so much value. No one knows how much, because the banks can't sell them, so banks like Citi keep taking writedowns, hoping to find the true value of their assets at some point. The exception, apparently, was Goldman, apparently because they sold small amounts of assets periodically, even as they were rising in value, in order to determine what their real market values were. This allowed them to detect falling confidence in the assets before the other banks did.