Donald Trump's A Total Sellout In the Hat Game

Donald Trump is already banking off his presidential win because his staple red "Make America Great Again" hats have flown off the shelves ... TMZ has learned.

The hat -- which retails for $25 -- was sold out following Tuesday's victory. Trump wore it throughout his campaign, but now that he's won it's more relevant than ever.

We're told it could take up to a couple of weeks to restock the now-iconic snapback.

Good news though for anyone still looking to grab one by the rim ... it's still available in white.