If the 400 richest Americans (top 0.0001%) liquidated 1% of their net worth, they'd have enough money to build housing for every homeless American, create an escrow to pay all the taxes, insurance, and maintenance on these properties for 10 years, and feed everyone in these facilities for 10 years.
And with what's left, each of the 400 could buy themselves a yatch, limo, and a helicopter.