What is short selling and why do investors do it?

For experienced traders and sophisticated investors, short selling can provide an opportunity to capitalize on falling markets. Investors use short selling when they feel that a company or sector is overvalued, with a view to profiting when its stock price drops.

However, short selling is an involved, potentially time-consuming investment strategy. And while it can certainly bring big returns, it can also result in big losses. 

How does short selling work?

When you go short, you expect a stock price to decrease. You borrow the stock from your broker’s inventory, the shares are sold, and proceeds are credited to your account.

At some point (ideally when the value has decreased considerably) you buy back (or “cover”) the same number of shares and return them to your broker. If the stock has fallen, you make a profit; if it has increased, you lose money.

What you need to sell short

Given the added risks involved, you will need to apply and be approved for short selling. You trade from a margin account into which you will have to deposit the full cost of the short sale shares plus anywhere between 30-100% of the value of your position as a margin deposit. If the stock price rises, you may have to add money to your account in what is known as a “margin call”.

There are several costs involved in short selling: trading commission, potential margin interest, and any dividends, distributions or rights declared during the period of the loan.

How you can win, how you can lose

You will make a profit if the selling price is considerably lower than your buying price. Let’s say you short 1,000 shares in Company Z at $25 per share. After two months you buy it back after shares sink to $5. Your gross profit is $20 ($25 - $5) x 1,000 = $20,000. You would then have to subtract your costs as described above (trading commission, potential margin interest, dividends, distributions, etc.), to calculate the net profit.

However, if those same shares were to rise in value, to $90 per share, your loss would be $65 ($90 - $25) x 1,000 = $65,000.

While your gains can only ever be as high as 100% of your investment, your losses can, in theory at least, be unlimited.

The pros of short selling

It is possible to make a profit from short selling because stocks and markets tend to fall much faster than they rise. For example, while the S&P 500 Index doubled between 2002-2007, it dropped by 55% in the following 18 months.¹

Famously, George Soros bet against the Bank of England in 1992 and when the pound fell, he made around US$1.5 billion in profit.² Jim Chanos of Kynikos Associates bet against Enron in 2001 and made big profits when it collapsed.³

Short selling can also be a useful tool for hedging portfolio risk—investors can protect their long-term investments by offsetting short positions.

The risks of short selling

You can stand to lose a lot of money. Tesla CEO Elon Musk has a fractious relationship with short sellers, who have been betting against his company for some time.⁴ After his tweet about taking Tesla private in August 2018, shares in the company shot up 11%, which cost short sellers around US$1.3 billion.⁵ More recently, short sellers collectively lost US$3.5 billion when Tesla’s stock rose in July 2024 after it reported better-than-expected deliveries.⁶

Sometimes you may be forced to buy back the stock early, known as being “bought in”. This can happen when the lender asks for the stock to be returned to sell it or they force the position to be closed if they become worried that heavy losses make it less likely that the shares will be returned.

This happens very rarely, however.

If a stock with very high short interest surges in price, it creates a short squeeze, which can force short sellers to close out their short positions, often at a loss.

Regulators may also impose bans on short sales in certain sectors or markets to avoid panic, leading to unexpected losses.

To succeed, short sales must be well-timed. You may be right about a company’s worth dropping but your timing must also be right. This dependency on timing means you have to keep a close eye on your positions. Day traders are in a good position to use a short selling strategy, because their activity level enables them to make quick trading decisions that make money or minimize losses. Of course, you don’t have to be a day trader to use a short selling strategy, but you should make sure you have the time to actively monitor your positions.

Shorting the market

If you are bearish on the whole market, you can sell short with inverse exchange-traded funds (ETFs) as well as individual shares. These ETFs are designed to make a profit when markets fall. For example, you can invest in ETFs that short the Toronto Stock Exchange, the S&P 500 Index and the 10-year Government of Canada bond.

Short selling with Qtrade Direct Investing

Qtrade margin accounts can be used for short selling, but investors have to meet certain conditions, including a minimum account equity of $10,000.

Shorting is allowed on senior stocks over $3 per share but not on junior stocks or senior stocks under $3. A “senior” stock ranks highest in terms of payout ranking, ahead of a “junior” stock, which has a lower claim on a company’s assets or income compared with senior stocks.

A mark to market (when the stock’s fair value is assessed, and margin is moved to/from your long account) occurs every Monday.

Learn more about short selling

Qtrade has a number of free resources that can help you to become better educated about short selling and stock trading in general. Our Guide to margin trading will show you how to use leverage to potentially increase your investment returns.

^{The information contained in this article was obtained from sources believed to be reliable; however, we cannot guarantee that it is accurate or complete. This material is for informational and educational purposes and it is not intended to provide specific advice including, without limitation, investment, financial, tax or similar matters.}