[Photo:  Tesla Cards  -  Steve Jurvetson / Wikimedida Commons]

Short-selling has perked up in 2016, and that means higher fees for lending securities.  Some $15 trillion in global lending programs generated $8 billion in revenue for asset managers and institutions.

Short sellers borrow or hypothecate shares to sell, betting they can buy them back at a much lower price later on. Securities lending allows fund managers and other big shareholders to make money on stocks by lending them out and earning interest.

Hypothecation means pledging an asset as collateral for a loan. If you use a margin account to buy on margin or sell short, for example, you pledge securities (stocks, bonds, or other financial instruments) as collateral for the debt. If the brokerage firm issues a margin call that you don't meet, it can sell those securities to cover its losses.

Overall short demand was stable this year but lenders were able to charge higher fees in 2016, partly due to a raft of violent market moves. The bulk of global securities lending revenues were derived from the U.S. and Canadian markets.

Short-selling in Tesla Motors stands out as a single source of revenue. The company’s stock was on a roller-coaster ride as analysts the electric car maker’s ability to meet production targets and questioned the bid to acquire SolarCity Corp. Tesla’s short-interest never fell below 15% of shares outstanding and the fee charged to borrow averaged 5% over in 2016. Lenders of Tesla shares split up $228 million securities-lending fees and by itself lifted revenue in the U.S. stock lending market over 2015.