(Why is the dollar gaining value?) When markets are crashing, investors need to get out from the loss of their investments and pay off their lenders, and that means selling off foreign assets. so money flows back to the U.S. dollar. (The Russian rubel and British pound fell to new lows against the Dollar and the Canadian dollar plunged as well. Is this all for the same reasons?) It's because of the losses in equities and credits and then the money flowing back to the Dollar. The Yen is strengthening against the Dollar, and Japan has no inflation problem and low interest rates. So the fact that the Dollar is still weakening against the Yen shows this doesn't mean there's more belief in the Dollar, but just a general weakening of confidence in the global economy. (Is it good to have a high currency value for the Dollar?) The other point to make here is that the weak dollar allowed the illusion that global markets weren't doing so badly, so people didn't realize how bad things were.