Yen

Yes, currencies around the world are dropping against the US Dollar... all except the Yen. This graph from INO shows how the US Dollar has dropped against the Yen since the latest market collapses. Japan is the largest foreign holder of US treasuries (source).

It is actually good in the long term for the Yen to go up in relation to the Dollar. Japan runs large current account surpluses while the US runs large current account deficits. A rebalancing of this situation will occur if the Yen appreciates over the long term.

In the short term, however, it is one possible avenue for capital flight. The market might just run away from the US and invest in the Yen.