When the upside is down: An intro to short selling of stocks

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Can you profit when price drops?

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It’s risky. It’s complex. And if you want approval, you have to jump through hoops. Sounds like the marketing pitch for an extreme sport, right?

It’s also a description of short selling, or “shorting the stock market.”

Short selling aims to profit from a pending downturn in a stock or the stock market. It corresponds to the trader’s mantra to “buy low, sell high,” except it leads with the “sell” part.

Suppose stock XYZ is trading at $100 per share, but you think it’s about to drop to $80 in the near future. If you could sell 100 shares of XYZ now, and buy them later at $80, you could gain $20 per share x 100 shares, or a $2,000 profit.

What if the price goes up instead? You tell yourself that if XYZ rises by $15 per share, you’ll cut your losses and buy the shares for a $1,500 loss.

This would all be easy if you already own 100 shares of XYZ. But what if you don’t? Depending on your account privileges, you may be able to do it anyway. That’s called selling short (or short selling). And it’s where things get tricky.

A stock represents a slice of ownership in a company, and the sale of a stock is a transfer of that ownership to someone else. But how can you transfer ownership of something you don’t own?

To sell short, you must first “borrow” the stock. Typically, your broker locates a stock lender, coordinates the transfer, and handles any associated fees. There are plenty of details:

There are other nuances, but you get the idea. Because of these costs and complexities—and risks, as we’ll see below—you need to qualify for what’s called a margin account.

Want to buy 100 shares of a $20-per-share stock for a brokerage or retirement account? Simple. Just pay $2,000—plus any transaction costs—and you own the shares. The most you can lose, if the stock becomes worthless, is $2,000.

Short selling is a different story. A stock can only fall to zero, but it can theoretically rise to infinity. That’s another reason short selling is typically done in a margin account.

Margin is a complex topic, but here’s the gist for short sellers: When you open a short position, you’re required to deposit and maintain a minimum amount of cash or other assets to help cover potential losses. If the market moves against you and the equity in your account drops below a certain level, you’ll need to deposit additional funds. This is known as a margin call. If a margin call isn’t met within a reasonable time frame, your broker might liquidate positions in your account, which could mean buying back your short position—often at the worst time.

In an extreme situation, a violent move upward can force short sellers to scramble to cover (that is, buy back) their positions. The mad dash pushes prices even higher, which triggers more margin calls and forces more scrambling by short sellers. This vicious circle is known as a short squeeze, and it’s a short seller’s worst nightmare.

It should be pretty clear now: Short selling isn’t for the faint of heart. That’s why it’s typically the domain of professional traders and deep-pocketed fund managers. But even if you’ve got the means and the moxie, make sure you know what you’re doing before selling short.