OK, for liquid cash I think you have to probably go with Treasuries as XboxBoy suggests. But that won’t protect you form excessive inflation or dollar decline. .

Best bet is to put what you absolutely need into secure, liquid assets (e.g. treasuries or spread out across several banks up to FDIC limits) and hedge your bets with a broad set of assets such as gold, real estate, long/short stocks in selected industries/countries.

Not many places to hide with ALL of the following: safety of principal, liquidity, and resistance to inflation/dollar decline.