Is it the S&P downgrade or something else?
Impossible to say obviously, but the mood in Asia was pretty ugly last night.
The Nikkei fell over 1%, but the big, standout loser was the Shanghai composite, which had actually been on a tear over the past several weeks. It fell 1.9%.
Markets in Europe are actually higher, as spreads come in a bit on sovereign debt amid rumours of ECB market involvement.