[gutnor]

The money is sitting outside the US because the companies do not need it in the US, or at all. They have literally no idea how to invest money faster than they can think of investment that would yield more profit than a tracker fund.

The only reason to move the money back to the US would be to hedge against a sudden rise of interest rate that would make funding hypothetical future US venture slightly more expensive. Obviously the rate at which such a hedging make sense is probably very low, single digit low.