NEW YORK (AP) – U.S. stocks are tumbling amid a rout in global markets after Standard & Poor’s downgraded the U.S.  credit rating for the first time.

S&P cut the long-term debt rating for the U.S. by one notch late Friday. The downgrade wasn’t unexpected, but it comes when investors are already nervous about a weak U.S. economy, European debt problems, and Japan’s recovery from its March earthquake.

Prices for Treasurys are rising because they’re still seen as one of the few safe investments. Gold topped $1,700 per ounce for the first time.