Meme stock mania of 2021: GameStop, AMC and the SEC report

In January 2021 a group of small, unloved companies became the most traded stocks in America. GameStop, a struggling video-game retailer, rose from $19.95 on January 12 to a $347.51 close on January 27 and an intraday high of $483.00 on January 28 (pre-split prices). AMC Entertainment, Bed Bath & Beyond, BlackBerry and a handful of others surged with it. The buying was organized loosely on social media, above all the Reddit forum r/wallstreetbets, and much of it came through new commission-free trading apps. The targets were partly the stocks and partly the hedge funds that had bet against them.

The episode, now called meme-stock mania, briefly broke the plumbing of retail trading: on January 28 several brokers stopped customers from buying the hottest names. This article explains what happened, what the SEC staff found in its October 2021 report, why the restrictions happened, and what changed afterward. The mechanics of squeezes themselves are covered in Short squeeze: how it works, warning signs and the GameStop case.

How it built up

GameStop had been a favorite of short sellers for years. Its stores were losing business to digital game downloads, and through most of 2020 its short interest hovered around 100% of the public float, according to the SEC staff. Short interest can exceed 100% because borrowed shares can be lent again (see Short selling explained: borrowing, fees, rules and unlimited risk). The borrowing cost was high: in the first half of 2020 the fee to borrow GME shares exceeded 100% a year at times.

A few individual investors argued online that the company was undervalued and that the short sellers were overextended. In January 2021 the story gained a catalyst: on January 11, GameStop announced that Ryan Cohen, co-founder of the online pet retailer Chewy, would join its board. The stock jumped, attention exploded, and on January 13 GME closed at $31.40, up from $19.95, on about 144 million shares, against about 7 million the day before.

Three forces then fed each other:

1. Retail buying. The number of accounts trading GME rose more than sixfold in a day in mid-January, according to the staff's analysis of the Consolidated Audit Trail.
2. Call options. Many buyers used cheap short-dated call options, which promised large gains on a big move.
3. Short sellers under pressure. Funds short the stock faced mounting losses. One prominent short seller, Melvin Capital, took a $2.75 billion investment from two other hedge funds on January 25.

The peak, January 22–28

On January 22, GME rose from $43 to $72 in about three hours, and 197.2 million shares traded, the most of the month. On January 26 and 27 the price went parabolic, closing at $347.51 on January 27, a gain of more than 1,600% from the January 11 close. On the morning of January 28 it touched $483.00.

On the split-adjusted monthly chart, GME closed December 2020 at $4.71 ($18.84 at the time), hit $120.75 ($483.00) in January, and fell to $9.63 ($38.52) at the February low. The log scale shows how extreme the January candle was: a range of nearly 30 times from low to high in a single month.

January 28: the trading restrictions

That day, Robinhood announced it would let customers only sell, not buy, eight securities, including GME, AMC, Bed Bath & Beyond, BlackBerry, Express, Koss, Naked Brand and Nokia. Several other brokers imposed their own limits. GME fell sharply from its morning high and closed the day far lower. Many retail investors concluded that the system had been rigged to protect the hedge funds.

The SEC staff report gives a more mundane explanation, rooted in settlement. Stock trades then settled two business days after the trade (T+2). Until settlement, the clearinghouse, the National Securities Clearing Corporation (NSCC), guarantees the trade and collects collateral from brokers to cover the risk that one side fails to pay or deliver. When prices swing by hundreds of dollars, that risk and the collateral jump.

• On January 27, NSCC made intraday margin calls totaling $6.9 billion on 36 clearing members, bringing total required margin to $25.5 billion.
• On January 28, NSCC waived a special charge for all members. Without the waiver, the staff wrote, one retail broker-dealer would have faced an extra charge of more than double its $1.4 billion margin requirement.

Brokers that could not easily raise that much cash, or feared they could not, cut their risk by stopping new purchases in the most volatile names. At a Congressional hearing on February 18, 2021, broker witnesses testified that the restrictions were a reaction to margin requirements, not to pressure from hedge funds. The staff report did not find otherwise, but it noted that firms restricted trading in ways some investors had not anticipated, and flagged thinly capitalized brokers as a risk.

What the SEC staff found

The staff report, published on October 14, 2021, is the most detailed public account. Its main findings on prices:

• Short covering was real but small. Buying by firms known to be covering short positions was a small fraction of total buy volume, and prices stayed high after its direct effect would have faded. The staff wrote that positive sentiment, not buying to cover, sustained the weeks-long rise.
• No gamma squeeze. A gamma squeeze occurs when options dealers who sold calls must buy shares to hedge as prices rise. Options volume did surge, but the staff did not find evidence of a gamma squeeze in GME in January 2021.
• Off-exchange execution. Much of the retail order flow went to wholesale market makers and was executed off exchange, out of public view, a structure linked to payment for order flow.

It closed with four areas for further consideration: the forces that can make brokers restrict trading (and shortening the settlement cycle as one remedy), game-like features in trading apps and payment for order flow, trading in dark pools and through wholesalers, and better reporting of short sales.

The aftermath

GME fell below $100 by early February, down more than 86% from its peak, then rebounded in late February and stayed volatile for months. AMC had its own, larger surge in late May and June 2021, and the company used the moment to sell new shares to the public. Many meme stocks later fell far below their 2021 highs, and Bed Bath & Beyond went bankrupt in 2023.

Policy changes followed over several years:

• T+1 settlement. In February 2023 the SEC adopted a rule to shorten the standard US settlement cycle to one business day. It took effect on May 28, 2024, halving the window in which a clearinghouse must hold collateral against unsettled trades. See T+1 settlement: trade date, settlement date and why they matter.
• Short-sale reporting. In 2023 the SEC adopted new rules requiring institutional managers to report short positions and lending activity, though parts of those rules were later challenged in court.
• Scrutiny of app design. Regulators examined "digital engagement practices," the confetti and notifications that encourage frequent trading, and how they interact with payment for order flow.

Lessons for investors

• Crowds can move prices far beyond fundamentals, in both directions. A stock that rises 1,600% in two weeks can lose most of that in two more.
• Short interest is a vulnerability, not a timer. GME's short interest had been extreme for most of 2020 before anything happened.
• Your broker's plumbing is part of your risk. Clearing deposits, settlement cycles and a broker's capital decide whether you can trade when you most want to.
• The losers are easy to miss. Headlines followed early buyers who sold near the top. Many people bought near the peak and held through the collapse.

How Finabase helps

Each symbol page shows the stock's short ratio (days to cover), volume and average volume, which is where the January 2021 setup was visible, and the GME monthly chart shows the whole episode on the same split-adjusted bars as the figure above. The trending page lists the most active and fastest-moving stocks each day, where today's meme-style moves usually show up first. Finabase is a research app; it does not execute trades.

Frequently asked questions

What happened with GameStop stock in 2021?

GME rose from $19.95 on January 12 to a $347.51 close on January 27 and an intraday high of $483.00 on January 28, 2021 (pre-split), driven by retail buying, call options and pressure on short sellers. It then fell more than 86% by early February.

Why did Robinhood stop people from buying GameStop?

Its clearinghouse demanded much more collateral as prices swung wildly. To reduce that requirement, Robinhood and other brokers temporarily allowed only selling in GME, AMC and a few other stocks on January 28, 2021.

Was GameStop a short squeeze?

Partly. The SEC staff found short sellers did buy to cover during the rise, but that covering was a small share of buying. Positive sentiment, not covering, sustained the rally, and there was no evidence of a gamma squeeze.

What did the SEC report on GameStop conclude?

The October 2021 staff report described the events and recommended further study of brokers' trading restrictions and settlement, game-like app features and payment for order flow, off-exchange trading, and short-sale reporting. It was a staff report, not a rule proposal.

Did meme stocks change the stock market?

They accelerated changes already under way. The US moved to T+1 settlement in May 2024, short-sale reporting rules were tightened, and retail participation and short-dated options trading remain far higher than before 2020.

Summary

In January 2021, social-media-driven buying, cheap call options and heavily shorted stocks combined to send GameStop up about 2,700% intraday in three weeks, with AMC and others close behind. Clearing collateral demands led brokers to restrict buying on January 28, and the prices collapsed soon after. The SEC staff's October 2021 report found that sentiment, not short covering, drove the rally, and pointed to settlement risk, app design and market structure as areas to fix. T+1 settlement in 2024 is the most visible legacy.