This is a FRED graph that is looking rather sad. It measures net capital inflow into the United States. The series stops in April 2008 so this doesn't measure anything since then, but if it did it would probably show some sort of upward trend. It matches the devaluation of the US dollar in the "cliff dive" at the end.
I'm not fully cognizant as to what it means, except that the jagged peaks and troughs since 2004 look very sharp and dangerous compared to pre-2000 levels. It also measures billions of dollars, which naturally go up when the money supply increases, which means that any pre-2000 comparison on the graph is probably nominal rather than real.