A short squeeze happens when short sellers increase stock prices by buying shares back quickly

Some experts and investors think short selling—a strategy in which investors bet that a stock will drop in value—helps keep the market healthy.

How a Reddit thread drove GameStop's stock price up and gutted the pockets of short sellers

In 2021, many hedge funds felt like GameStop was overvalued and began placing short positions. However, users in the "r/WallStreetBets" subreddit felt like the hedge funds were too aggressive in their short positions and rallied together to purchase large amounts of GameStop stock, pushing the stock price up. As the stock price rose, hedge funds began buying back their shares to cover their short positions, which also began pushing the stock price up in what's called a "short squeeze."

Shorting is a high-risk and expensive investment strategy that hedge funds specialize in

Most investors buy stocks with the expectation that those stocks will be worth more tomorrow than they are today. Short selling, known as “shorting,” a stock is the opposite: The investor is betting the stock will drop in value.

Bear raiding is a manipulative tactic to bring a stock price down—and part of why short selling can be controversial

Bear raids occur when short sellers use manipulative tactics—like spreading false rumors or coordinating trades—to artificially drive down a stock's price and profit from short positions. Although bear raids are an illegal form of market manipulation, they can spook investors, prompting large selloffs of shares and causing a company's value to plummet. As a result, investors may be hesitant to invest in the company in the future, creating a feedback loop of stock downturn.

Stock buybacks are when a company purchases some of its own shares of stock

This reduces the number of shares on the market and, therefore, makes the remaining shares more valuable. Buybacks have received a lot of criticism in recent years for many reasons, such as how they could artificially inflate share prices.

Read about why bans on short selling are a controversial policy

Generally, short selling is legal, but regulations often restrict short positions when a stock has experienced a sharp price decline (more than 10% in one day). However, negative feedback loops in times of financial crisis have given short selling a bad reputation. The government has temporarily banned short selling during previous market downturns—like The Great Recession of 2008 and the early months of the COVID-19 pandemic—but experts argue whether those bans actually improved market stability or just distorted prices.

Hear why one short seller thinks short selling is now more important than ever.

In 2012, Bill Ackman's hedge fund, Pershing Square, took a $1B short position against supplement company Herbalife after discovering that 82% of the company's distributors never made a profit, calling it a true pyramid scheme.

Many hedge funds use short selling as an alternative investment strategy to offset risk

Hedge funds typically use a "long-short" investment strategy—where funds diversify by investing in a mix of long positions and short positions—to balance risk and maximize profits. Including short positions gives hedge funds some protection against downturns in the market, although the strategy can have uncapped losses for investors.

In early 2021, GameStop's stock surge brought retail investing into the spotlight

Using platforms like Robinhood, everyday investors became a growing presence in financial markets during the Gamestop short squeeze, revealing the influence retail investors can have on the market.

Investors need a 'margin account' to short sell stock

Margin accounts are leveraged accounts through brokerage firms that allow investors to make trades without the full amount of capital on hand. Similar to a secured loan, margin accounts often require some form of collateral and typically have a cap on how much investors can borrow. However, trading with a margin account is much riskier than a traditional investment account. Fees and charged interest are due on margin accounts, regardless of trade performance, meaning it's possible for investors to lose more money than just their initial investment.

'Buying the dip' refers to purchasing stocks or ETFs after a price decline in anticipation of a rebound

Some investors see it as getting a discount before the market recovers and the temporary declines turn into gains.

Tesla short sellers benefited from the company's poor performance in 2025

Tesla was widely considered the most-shorted stock until 2024, despite consistent short-seller losses. Between 2016 and 2020, short sellers reportedly lost more than $11B as Tesla's stock price continued climbing. However, long-held short positions began paying out in 2025 as Musk's foray into politics and his eventual feud with President Trump hurt Tesla's stock performance. In 2025, Tesla short sellers made more than $10B.

Retail investors are getting burned by long/short strategies

In the US, many retail investors lack the SEC-mandated status (a high enough net worth, income, and other factors) to directly invest in hedge funds. The regulator considers hedge funds too risky for the masses. Hedge fund-like strategies have emerged as a workaround, despite potential pitfalls.

Porsche briefly made Volkswagen the most valuable company in the world in 2008

In the wake of the 2008 global financial crisis, hedge funds began placing short positions on German automaker Volkswagen. Around the same time, Porsche began acquiring a majority stake in Volkswagen, which decreased the amount of available shares, or the "stock float." Porsche then announced that it owned more than 74% of the company, prompting short sellers to realize they had placed more short positions than were logistically possible given that less than 6% of the company's shares were available to trade. In what is largely recognized as the biggest short squeeze in history, Porsche made $10B, and hedge funds lost more than $30B.

A 'position' in financial markets refers to the amount of a security or asset that an investor owns or sells short

A "long" position gains from an increase in a security's price, whereas a "short" position profits from a price drop. This article includes a detailed explanation of the term "position" as it relates to investing and financial markets.

See a real-time list of the most shorted stocks in the US

Every two weeks, the Nasdaq and New York Stock Exchange release the stocks with the most short positions. Some of the companies with the highest short positions as of early 2026 were Hims & Hers and Groupon.

While day trading has risen in popularity in recent years, the SEC warns it is a speculative strategy that can cause big losses

A day trader is anyone who buys and sells a stock within the same trading day. They quickly move in and out of the market to try and profit. Some day traders are professionals, while others are retail investors.

The 1929 stock market crash is a defining example of a financial bubble burst

Fueled by margin speculation and intense optimism, stock prices soared to unsustainable levels before collapsing in late October—erasing billions in market value within days.

What are repurchasing agreements?

Repurchasing agreements are short-term trade agreements in which a dealer sells securities and agrees to repurchase them at a higher price soon after (often within 1 to 2 days). This gives dealers quick access to cash and allows the purchasing party, often the Federal Reserve, to control liquidity in securities. This can be used to alter the money supply, which is a key element in combating deflation.

How one supplement company cost a short seller $1B

Pershing Square, a hedge fund founded and run by Bill Ackman, put short positions on Herbalife in 2012, because it believed the company was a pyramid scheme. Ackman's longtime rival and legendary investor Carl Icahn began buying Herbalife shares, causing the stock price to rise—ultimately hurting Pershing Square's short position.

A margin call is a way for traders to pay off debts by selling a security before they may be ready to do so.

Hear how the Piggly Wiggly grocery store founder attempted to squeeze short sellers by cornering the grocery store's stock

Founded in 1916 in Memphis, TN by Clarence Saunders, Piggly Wiggly was the first modern grocery store with aisles for customers to shop for themselves. In 1922, investors placed short positions, sensing that the stock may be overvalued after several Piggly Wiggly franchises in the Northeast went bankrupt. Saunders attempted to squeeze short sellers by taking out $10M and buying up nearly 99% of all available Piggly Wiggly stock. Ultimately, the fiasco ended with Piggly Wiggly's stock being permanently banned from the New York Stock Exchange and Saunders leaving Piggly Wiggly and filing for bankruptcy.

Activist investors use large ownership positions to influence companies

By holding large ownership positions, which often come with leveraged access to a company's board or the ability to force a shareholder vote, activist shareholders can change a company's corporate governance, leadership, and overall direction. Critics argue that activist shareholders hurt companies in the long term by prioritizing short-term higher shareholder returns over sustainability and growth efforts.

Meme stocks often have little underlying value but are fueled by crowd funding

"Meme stocks" is a phrase originating in the early 2020s, referring to companies with little underlying value who gain recognition through social media and whose stock price experiences rapid gains.

'The Great Onion Corner:' Hear how short-selling onions ended with a ban on onion futures

In the early 1950s, onion farmer and produce trader Vince Kosuga cornered the onion market, resulting in a 1958 ban on onion futures from Congress. After stockpiling onions and buying onion futures, Kosuga then began shorting them. Then, he released his accumulated surplus of onions, driving the price down to essentially zero, and cashed in his short positions.

Insider trading is the practice of trading a company's securities based on material, nonpublic information.

Indicators of economic bubbles include euphoric narratives and extreme valuations.

How one man placed the first short against the Dutch East India Company

Isaac Le Maire, a Dutch businessman and cofounder of the Dutch East India Company, is said to be history's first short seller, betting against the Dutch East India Company's stock price. Le Maire, who had been fired from the spice trading company over an unclear financial dispute, began spreading false rumours about the company to encourage people to sell their stock in order to tank its value.

Shares are parts of a stock that represent ownership of a company

Shares are traded on the stock market. Once you buy a single share of a company, you are considered a shareholder of that company and may have certain rights as a partial owner, such as voting on business decisions.

Private equity firms often use leveraged buyouts to acquire new companies

In a leveraged buyout or "LBO," private equity funds finance acquisitions with debt secured by the target company's assets and cash flows. The PE firm aims to improve operations and leverage the company's profile to pay down debt, thereby increasing equity value.

Who is Michael Burry?

Michael Burry is best known for shorting the mortgage bond market in 2007. Before the Great Recession, the legendary investor’s firm took a stake in GameStop and argued the company was being undervalued in 2019. Learn more about Burry’s historical impact on markets here.

SPACs, explained

Special purpose acquisition companies make it easy for mature unicorns (companies valued at over $1B) to receive growth capital by going public. This process effectively skips the work of a traditional initial public offering, and its time-intensive investor negotiations. Typically, a well-known investor with expertise in a certain industry sponsors a SPAC with the intent to acquire a startup. Learn how it works and the risks involved here.

In 2008, the 'Big Short' mastermind Michael Burry made more than $700M.

'The stock market' can be loosely defined as a set of exchanges and other places where shares of public companies are bought and sold.

GameStop stock began a meteoric rise in January 2021, rallying from a low of $2.57 to as high as $438 when Keith Gill helped mobilize retail investors to drive prices higher

Keith Gill was a financial advisor who posted on social media under usernames including "Roaring Kitty." Backing from Chewy founder Ryan Cohen, who became GameStop's CEO, took things up a notch.

Many investment bankers work on IPOs

When a company undertakes an IPO, investment banks often buy many of the organization’s shares directly from the company, in order to sell the shares on the stock market. The bank stands to profit after marking up the shares.

Leveraged ETFs made headlines in 2026 as a boom in single-stock leveraged products tied to AI companies drove volatility and record retail demand.

Millions of Americans will be invested in SpaceX because of the fast-tracked process to list SpaceX on the Nasdaq 100, and, subsequently, the index funds that track it.