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

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

A landmark hedge fund court case once reshaped high finance

Hedge fund traders tied to insider trading by probing prosecutors are relatively rare. When billionaire hedge fund legend Steve Cohen, founder of SAC Capital, pleaded guilty to trading on inside information, Wall Street trembled. The outcome of the case remains a cautionary tale for traders today.

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.

Retail investors are individuals who trade stock for themselves

Institutional investors, on the other hand, are investing for someone else. There are big differences between the two, one being that institutional investors can be granted certain special treatment (like being able to purchase IPOs right away).

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.

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.

Prediction markets and sports betting are not forms of investing, despite how some fans portray them.

Prediction markets help people bet on almost anything—which can be controversial

Critics point to incidents such as traders placing bets on the Venezuelan President Nicolás Maduro's capture and the two people in Israel who were charged on suspicion of using classified information to place bets about military actions.

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.

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.

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.

Prediction markets convinced regulators they're not gambling, but exchanging commodity futures contracts

Kalshi built a legal case that argues its yes/no bets on real-world events are futures contracts, and the relevant regulator—the Commodity Futures Trading Commission—agreed in 2020. Many states are now suing major prediction markets, arguing this legal case is faulty and obscures the true substance of the business: gambling.

What is after-hours trading?

While both the New York Stock Exchange and the Nasdaq open at 9:30 am ET and close at 4 pm ET, some trading is allowed after that. After-hours trading was once only open to institutional investors and people with particularly high net worths. Now, with the advent of computers, anyone can trade stocks anywhere online, and those regulations have broadened.

Prediction market Kalshi's CEO Tarek Mansour ​​has said that prediction markets are similar to the stock market—except instead of buying and selling shares of companies, users buy and sell "yes" or "no" on whether an event is going to happen or not.

Play a game that reveals if investors with a crystal ball make better trades

The "crystal ball" game reveals how well you would do trading stocks and bonds if you could see the front page of the Wall Street Journal one day in advance.

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.

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.

Read about the day Palantir went public in 2020

After more than 15 years in business, Palantir held its initial public offering (IPO) via a direct listing—meaning the company didn't rely on underwriters to assess the initial trading price or stock value. Palantir's stock ended the day trading 31% higher than the reference price.

Some private credit funds trade on the stock market

These funds, which trade at market prices, are called "public BDCs," which stands for "business development companies." For instance, the global alternative investment manager Ares Management Corp. has a public BDC.

Commodity traders are most commonly 'hedgers' or 'speculators'

While hedgers often produce and consume physical commodities (like corn, copper, or natural gas) and use the markets to manage the price risk for those commodities, speculators provide liquidity by betting on commodity price changes.

How prediction markets differ from sportsbooks matters for regulation

There are a number of differences and similarities between sportsbooks and prediction markets, despite both allowing people to bet on outcomes for sports-related events. For instance, prediction markets typically earn revenue through transaction fees rather than taking directional exposure to outcomes.

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.

40 key stock market terms, explained

Liquidity. Forex. Capitalization. Blue chip stocks. These are just a few pieces of stock market vocabulary most people who don't spend all day on a trading floor might not know. Thankfully, we found a fun infographic that makes it easier to learn what 40 key stock market terms mean and why each of them matters.

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

Initial public offering (IPO) is the term for when a company goes public

When a company completes its IPO, it's no longer a privately owned organization. Anyone can invest in the company by buying its shares on the stock market—opening up ownership of the business to the general public.

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.

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.

Retail investors are average joes, while institutional investors often move billions of dollars a day

Retail investors often trade 100 shares at a time, while institutional investors trade 10,000 or more. The biggest difference is that, unlike retail investors, institutional investors are professionals who are trading someone else’s money.

The number of publicly traded companies has decreased in recent years.

In 1996, more than 7,300 companies traded publicly on US stock markets, but that number has recently dropped to 4,300. Economists point to two reasons: First, going public requires full disclosure of operations, exposing it to scrutiny from investors, competitors, and analysts. Second, the IPO process is expensive and time-consuming.

Private companies are often harder to value than public companies

That's partly because there isn't readily available stock information, and financial accounting is kept behind closed doors. Typically, determining the value of a private company involves, among other things, closely comparing the private company with its competitors.

An S-1 reveals financial and other details to the public, often for the first time, when filing for an IPO

To file for an IPO, a company must file a registration form called an S-1 or prospectus with the US Securities and Exchange Commission. S-1s detail a company's current business model, competitive landscape, and other financial information.

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.

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.

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.

Private credit is a nonbank loan made directly to a business

Similar to private equity, private credit is part of the private markets world. Both strategies offer illiquid, privately negotiated investments for privately held companies. Unlike private equity investors, however, private credit investors typically do not take ownership stakes in the companies they invest in.

Why does the stock market matter?

Open any newspaper, turn on your local TV news station, or listen to a daily business radio segment, and you’re bound to hear about how the stock market is performing. Netflix created a 17-minute (free) explainer that dives deep into the nitty-gritty of how we got here.

An initial public offering is how a private company becomes public.

This milestone requires plenty of preparation, starting with the SEC's S-1 registration, revealing key details about the company's finances and strategy. Investment bankers set valuations, secure long-term investors, and finalize share pricing before the public launch. IPOs provide companies with significant capital, but also demand transparency and invite public scrutiny.