Why? If you bought in March, you have magical returns on the table, but you must harvest. You must sell to realize those gains. September is the last possible moment when you can sell, and book profits for Fiscal 2009 if you are a major-league investment fund manager. Let's not play coy about it either: These investment managers are the ones who determine the course of the market.
Take my uncle, for instance. He took a $1,000 gamble on Citigroup when they were down to $0.97 per share in March. They hit $5.05 a couple of days ago. He had $5,200+ awaiting him if he sold at that moment. I sure hope he did. They are down to $4.65 right now. He would have realized a magical 520% plus return in just 6 months of waiting if he sold a couple days ago. He can then wait for it to drop to 2.50 or 3.00 and then increase his holdings. You wait for the next 5.05 and dump again. This is how the game is played. It's just like getting a couple of first downs before the touch down.
A similar story is in progress for all investment funds. They will sell. Massive sell-offs will produce massive downward spirals in price. It doesn't matter to the investment fund manager. He can still book new profits. He will do it.