Unfortunately, that's an urban myth. If you don't want your shares loaned out, you need to keep them in a "cash" account. If the shares are in a margin account, then as part of the brokerage agreement that you agreed to for the margin account, the brokerage has the right to loan out your shares to shorts. Feel free to call your brokerage up to confirm. FYI I already checked previously with TDA and Schwab.