sell short

Verb	1.	sell short - sell securities or commodities or foreign currency that is not actually owned by the seller, who hopes to cover (buy back) the sold items at a lower price and thus to earn a profit
	2.	sell short - underestimate the real value or ability of; "Don't sell your students short--they are just shy and don't show off their knowledge"

commerce, commercialism, mercantilism, sell