Buy GameStop, Fight Injustice. Just Don’t Sell.

It has been a year since Mat Bowen, who was the pastor of a small church in Gibson City, Ill., had the dream — the one where Elon Musk, the head of Tesla, urged him to buy Dogecoin.

Mr. Bowen had just begun to dabble in investing. He soon discovered WallStreetBets, the online forum on Reddit where throngs of small investors were plotting to buy shares of GameStop, the troubled video game retailer, in a bid to teach Wall Street a lesson. Some hedge funds had bet that shares of GameStop would fall. Instead, they took off, as the investors banded together last January to drive the price up more than 1,700 percent.

Caught up in the frenzy, Mr. Bowen bought GameStop, too. In July, he quit the church to become a full-time trader, convinced he was joining a fight against financial injustice.

The beliefs underpinning last year’s meme stock phenomenon are stronger than ever. For a large number of individual investors, the stock market has become the battleground on which they join forces to right perceived wrongs and fight the powerful. So much so that when the stock market seesawed this past week, many small investors were undeterred. Falling prices were another opportunity to buy more shares of their favorite companies.

“The reason I am still in this, and the reason I am willing to ride these stocks to zero, is for my fellow citizens,” said Mr. Bowen, who received his master’s degree in divinity at the Princeton Theological Seminary. He cast the so-called meme stock fight in moral terms. “The battle of good versus evil is not just limited to the walls of a church or a synagogue or a mosque,” he said.

GameStop was the coming-out party of sorts for a sweeping change in stock market investing that had been bubbling since the start of the pandemic. Stuck at home, flush with government stimulus checks, known as “stimmies,” and watching the stock market rise to nosebleed levels even as the economy teetered, millions of small investors began to take tentative steps into trading in the spring of 2020.

Many were guided by an online community of die-hard traders determined to make money in a world they saw as being manipulated by big Wall Street firms. Together, they turned investing into a mass movement that was personal, with a decidedly anti-expert, anti-Wall Street bent.

The new traders often refer to themselves as “apes” in homage to “Rise of the Planet of the Apes,” a 2011 film in which apes challenge human domination. They appear to largely be men in their 20s and 30s. On social media forums, they present alternative ideas about trading and vent about how the wider system is rigged against them. A theory has taken hold that Wall Street firms, in cahoots with regulators, have created “synthetic” or fake shares of GameStop as part of an elaborate profiteering strategy — and that they must be stopped.

In interviews, investors whose lives and beliefs changed significantly as a result of the money they put in meme stocks spoke about the community that investing had given them and their faith in the information they had gleaned from their networks.

“This is our moment in history for financial injustices,” Mr. Bowen, 30, said. “We are here to stay for those financial changes so there can be a free and fair market.” Along with GameStop, shares of AMC Entertainment, the struggling movie theater chain, and Sundial, a marijuana company, account for a quarter of his portfolio, he said.

When GameStop shares soared last January, Robinhood, the commission-free trading app popular with small investors, temporarily restricted trading in meme stocks, citing Wall Street regulations and liquidity issues. GameStop’s shares crashed from nearly $500 to $40 in three weeks, causing big losses for investors. They have since recovered to trade around $100, although the company mostly posts quarterly losses.

AMC, the other big meme stock that many traders believe Wall Street is also manipulating, is trading around $15, only slightly higher than it was a year ago, despite briefly popping to $60 in June. The company’s outlook is uncertain, but the stock’s fate is clearer: The public — as opposed to institutional investors or insiders like Adam Aron, the chief executive — controls the majority of AMC’s shares.

Harrison Fritz, a 25-year-old who works in the finance industry, had invested $8,000 — most of his savings — into GameStop shares last January, lured in by the possibility of profit. But the abrupt shutdown in trading upset Mr. Fritz. Big guys on Wall Street had decided to cut little guys off in the middle of something, he felt. Why were they allowed to do that?

“It created a huge, deep-seated hatred and feeling of being robbed of what could have been life-changing money for many people,” Mr. Fritz said. “You really saw the movement change from being about financial gain to being a way to sort of get back at ‘the man.’ Many people on Reddit began using the terminology ‘revolution.’”

Kunal Gogna, a 36-year-old clinical data scientist in San Diego, began trading stocks at the beginning of the pandemic. Knowing nothing about finance, he began by following the advice of Keith Gill, a 34-year-old Massachusetts man who called himself Roaring Kitty. Mr. Gill had invested heavily in GameStop’s stock and was encouraging others to join him beginning in mid-2019.

“He provided a very clear thesis,” Mr. Gogna said, explaining that Mr. Gill’s work was an accessible contrast to other information — “charts, all these dizzying things” — out there. “It can be overwhelming,” he said, “and I think that’s designed to keep the normal people away.”

By January 2021, Mr. Gogna was “all in” on GameStop shares because he believed that the company would eventually pivot to a digital business. “Every pay period I literally buy as many shares as I can,” he said, speaking from a hospital in San Diego where his wife, a nurse, was in labor with their first child. Mr. Gogna said he had persuaded her to move her savings into GameStop as well. (She delivered a healthy baby.)

As he dug deeper, spending hours reading what other traders had posted about GameStop, Mr. Gogna became convinced that something far darker was going on. Several posts detailed what users were calling a plot by Wall Street, the Securities and Exchange Commission and a trade clearinghouse to create fake or “synthetic” GameStop shares.

The goal of the plot, according to the posts, was to help hedge funds pull off the short trade they couldn’t last year. Shorting a stock involves an investor’s borrowing shares from another and immediately selling them, hoping that their price will fall and that the investor can buy them back cheaply, return them and pocket the difference. The theories were circulating on a Reddit forum called Superstonk, which had been created in March, after GameStop had receded from the headlines, by die-hard fans of the company. There are detailed research papers called “due diligences” — DDs for short — laying out far-fetched theories about how various Wall Street actors were secretly manipulating GameStop and other meme stocks.

A core premise of the plot’s existence is that the short interest in GameStop — or the amount of shares held short — is higher than 100 percent. The only way to counter the plot is for individual traders to buy GameStop shares at any price to keep them from falling — the “mother of all short squeezes,” or MOASS. Mr. Gogna is among the traders who have pledged to “hold on for dear life,” or HODL, as the acronym goes.

Frank Partnoy, a law professor at the University of California, Berkeley, said synthetic shares can exist because the same shares are often lent out to multiple short sellers at once, creating the impression that there are more shares than there really are. But, he added, “it’s not true that the S.E.C. would be involved, and it’s not easy to do something like this. And it also would be manipulative, so it would be illegal.”

The Superstonk discourse shows how the gospel of meme stocks has taken hold among a wide range of investors — from those who no longer buy into it, like Mr. Fritz, to others who accept it without question.

“I can’t explain it all,” said Ben Pomeroy, 38, who lives in Columbus, Ohio, and works for a manufacturing company. “I read it, and I was like, ‘OK, that makes sense,’ but if you asked me to explain it I don’t think I could give you a very coherent answer as to why these synthetic shares exist.” He has continued to add to his GameStop position.

Jesus Gonzalez was drawn into the meme stock trade by what he saw as a power imbalance. Mr. Gonzalez, 22, had invested in stocks off and on as a teenager, but “AMC and GameStop are different from any other play in the stock market,” he said. “We have never seen a congregation of retail investors who have collectively come together on the internet and formed the largest, most powerful decentralized hedge fund in the world.”

Mr. Gonzalez, who graduated from Arizona State University with a bachelor’s degree in finance last month, is buying more shares of GameStop and AMC, even though his $220,000 portfolio is off 37 percent from its November high, he said.

His 34-year-old sister, Ruby Gonzalez, a behavioral health therapist who works at Phoenix Children’s Hospital and is studying to become a nurse, followed her brother’s lead and invested most of her savings in the two companies. “I want to change market manipulation,” she said.

Mr. Fritz dropped out of the so-called battle after he noticed that Superstonk’s moderators would quickly delete posts that introduced “fear, uncertainty and doubt” about the GameStop theory. In May, he sold his shares of GameStop, walking away with a “very small” net gain. Most of his money is now in “far more boring, safer investments” like exchange-traded funds, Mr. Fritz said. (He didn’t want his location or job title disclosed in this article because he was afraid that his decision to share his views about his change of heart could invite real-world attacks from other people posting on Superstonk.)

Unlike Mr. Fritz, who popped in and out of the Reddit world, Blayne Macauley, a 38-year-old artist in Atlanta, never bought into the conspiracies or saw trading as a way to get back at Wall Street.

Ms. Macauley got into buying and selling stocks earlier in the pandemic. Curious about the GameStop frenzy last January, she put $25,000 into a brokerage account to invest largely in meme stocks. Her largest position was in AMC, which she bought for roughly $4 a share and sold after the shares recovered from a dip in February.

The meme stock craze showed her that she could make money off buying and selling stocks, but it also reshaped the way she spends her time. “It became quite the addiction,” said Ms. Macauley, who now trades daily, mostly in options. All she has since wanted to do is talk stocks, so she created a podcast with her brother-in-law to do just that.

“There is this whole community of people who have built up around the podcast and are invested in me doing well,” Ms. Macauley said. “That has been life changing for me. So in that way,” she added, using the stock symbol for GameStop, “the GME AMC squeeze changed my whole life.”