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

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

When short sellers realize their positions may be incorrect—usually triggered by increasing share prices—they often try to quickly buy back their shares in order to minimize their total losses. When this happens on a large scale, that buying activity can drastically increase to represent the seemingly high demand for that stock. The result is called a "short squeeze," which refers to short sellers literally being squeezed out of their positions by rising prices.

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.

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.

How did the bull and bear markets get their names?

The terms "bull" and "bear" are used to describe certain sentiments or activities in the financial markets. A bear market refers to declining stock prices and pessimistic outlooks, whereas a bull market represents the opposite.

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.

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.

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.

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."

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.

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.

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

Retail investors are not professionals—they invest their own money

For retail investors, the stakes may seem higher and more personal. Critics say that this dynamic means that retail investors are more susceptible to behavioral biases that could lead them to make poor decisions when it comes to buying and selling assets. For instance, fear of missing out could cause a retail investor to buy a stock that is popular but not a financially worthy investment.

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.

Active investors try to 'beat' the stock market's performance

There are two primary types of investment strategies that professional investors use: active investing and passive investing. While active investors try to "beat" the stock market's performance, passive investors have a bit more faith in the system.

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

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.

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.

In March 2008, Bear Stearns was the first major bank to collapse in the Great Recession—leading to panic across the entire global financial system.

Smart pricing algorithms can unintentionally work together to raise prices

Researchers have found that, through trial and error, algorithms designed to adjust prices based on market data can learn to mimic price-fixing tactics, even without explicit programming to do so. Over time, they "learn" that it is more profitable to avoid price wars and keep prices high when competitors lower prices.

Chapter 7 and Chapter 11 filings can impact common stockholders

Publicly traded companies don’t file for bankruptcy out of nowhere—there are typically warning signs in a stock’s performance, quarterly earnings calls, and US Securities and Exchange Commission filings.

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

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.

Just because a big name company is going public doesn’t guarantee a successful stock

A reporter dove into how highly anticipated IPOs can still be risky, and why retail investors should be wary of investing right away.

Some companies like to make their IPO day antics unique.

An article details some of the wildest bell-ringing day stunts in recent history, from Clifford the Big Red Dog ringing the opening bell to one company's employees roasting marshmallows in a campfire on Wall Street as it went public.

BlackRock sponsored the Federal Reserve's purchasing of corporate debt through exchange-traded funds during the COVID-19 pandemic, while it simultaneously sold some of its own shares on the secondary market—sparking controversy over potentially unfair advantages.

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.

Private equity deals sometimes come with layoffs.

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.

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.

Fancybear: The state-backed hacker cell

Fancy Bear (APT28) is a Russian-based hacker group that targets a variety of organizations across the globe. Learn how to prevent Fancy Bear.

The Reddit forum r/WallStreetBets is a place to discuss high-risk trading strategies

r/WallStreetBets is a forum (aka a “subreddit”) on the social media platform Reddit that was started in 2012. Later, r/WallStreetBets evolved into a place where unconventional investment approaches were not just tolerated, but planned and celebrated. It’s perhaps most famous for its role in the GameStop saga.

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.

Special-purpose acquisition companies let companies skirt the IPO process

A video explains how private companies have taken advantage of this loophole, why investing in these companies isn’t always a good idea, and how blank-check companies (as they’re commonly called) work.

Prediction markets—the platforms where users can trade bets that pay out depending on certain event outcomes—have faced questions about insider trading.

'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.

Marketers often use psychological tactics to sway consumer action

From making someone feel as though a resource is scarce (“only one item left in stock!”) to invoking a sense of authority (“top dentists recommend this toothpaste”), marketers use a variety of psychological tactics to elicit a desired response from their target audience.

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.

Standard Oil's predatory business practices included temporarily operating at a loss to drive competitors out of business

Rockefeller's oil monopoly had a dark side, including cutting oil prices so low that Standard Oil was sometimes temporarily operating at a loss in order to drive competitors out of business.

Famed American investor Jesse Livermore made millions when the stock market crashed in 1929

Livermore made his first major short against rail company Union Pacific in 1906, coincidentally before an earthquake in San Francisco, which ultimately tanked share prices. During a financial panic the next year, JP Morgan reportedly asked Livermore to increase his long-term investments to restore hope and restabilize the market—which Livermore did. However, Livermore began betting against the market in 1929, sensing that stocks were too hot, and was one of the few people to benefit from the 1929 stock crash.

Private equity firms can be 'powerful partners' or 'formidable competitors'

Under the best circumstances, PE firms can increase a company's value using strategies that might not be suitable for public companies facing pressure for immediate shareholder returns. But PE firms are often portrayed negatively due to the aggressive strategies they sometimes use to cut inefficiencies. As PE has grown, many firms have changed their strategies, shifting away from aggressive scaling to more integrated acquisitions.

Investing in bonds comes with a few risks

Think: changes in interest rates that impact the bond’s value, or a bond issuer completely defaulting on a loan. There are steps investors can take to lower their initial and future risk when investing in the bond market, such as checking a company's bond rating before investing.

Tax-loss harvesting is a way that some people attempt to trim their tax bills

Specifically, tax-loss harvesting is a way to lower your tax bill by offsetting investment gains with losses. It can be tricky to practice and comes with a few important rules, so working with an expert may be your best bet before Tax Day.

Prediction markets have their own lingo that's an amalgamation of Gen Z and Gen Alpha slang

For instance, if you've been out-maneuvered by another trader, you've been "mogged." A "rulescuck" is someone who is a stickler for betting market rules and may try to win on a technicality.

The Beanie Baby craze is known as one of the wildest collectible bubbles in history

The Beanie Baby boom saw collectors drive prices for stuffed animals into the hundreds or thousands of dollars, fueled by hype surrounding scarcity and online bidding wars. When demand collapsed in the early 2000s, the market crashed—leaving steep losses for many speculators.

How to put on a hedge

These days, hedging your portfolio isn’t just for hedge fund managers. An explainer from Robinhood delves into what a hedged position actually is, why traders put on hedges, and how you, too, can work to guard your holdings against a market downturn. The idea is to derive gains from your portfolio when markets are trending up, down, or sideways.

BlackRock played an integral role in the Federal Reserve's response to the Great Recession, managing about $30B of hard-to-sell Bear Stearns assets on behalf of the New York Fed.

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

How ‘vulture’ hedge funds make money

Some hedge funds specialize in snapping up distressed assets, like failing newspaper chains, and further stripping down their operational expenses in a bid to make a profit from the initial capital outlay. Delve into how one secretive firm known for the practice operates—and what’s at stake for the broader economy.

Bank runs, explained

A major feature of the modern financial system is trust: if an institution loses it, customers will quickly withdraw deposits and stockholders will sell their shares. This digestible animated video looks into the nature and history of bank runs and...

A barbell investment strategy focuses on balancing high-risk and low-risk investments

Barbell investment strategies emphasize bypassing medium-risk investments in favor of combinations of high-risk and low-risk investments. The idea is that the stability on the low-risk side offsets the volatility on the high-risk side, and would look like a barbell with two large weights on either end of the bar.