In that case, “those 19 stocks may be more difficult to borrow, and the cost of borrowing would likely rise,” said Russell Kamp, the New York-based chief executive officer of the global structured product group at Invesco. One prime broker, who declined to be identified, said it’s a good bet that the costs of borrowing shares will head higher. For now, market veterans say any upward pressure on shorting costs is likely to prove manageable.