Most likely, the vast majority are not in circulation but stored somewhere and are outside the US anyway. A stack of $100 bills is probably the best long-term i

Most likely, the vast majority are not in circulation but stored somewhere and are outside the US anyway. A stack of $100 bills is probably the best long-term investment for illegal funds that will be used at some point in the future. It's relatively easy to transport, valid until eternity (other than e.g. UK where bills are taken out of circulation every few years or decades) and accepted world wide.