One day in July 1985, three young men from Philadelphia, their lawyer and a burly Pinkerton guard arrived at a horse track outside Chicago carrying a briefcase with $250,000 in cash.

Running the numbers on a Compaq computer the size of a small refrigerator, Jeffrey Yass and his friends had found a way to outwit the track’s bookies, according to interviews, records and news accounts. A few months earlier, they’d wagered $160,000, gambling that, with tens of thousands of bets, they could nail the exact order of seven horses in three different races. It was a sophisticated theory of the racing odds, honed with help from a Ph.D. statistician who’d worked for NASA on the moon landing, and it proved right. They bagged $760,000, then the richest payoff in American racing history.

But that summer day, when they presented their strikingly long list of bets at the track window, they were turned away. Their appeal to the track owner got them ejected. Yass, just 27, then sued for the right to place the bets. The track’s lawyer fumed to a federal judge that the men were trying to corner the betting market “through the use of their statistics and numbers.”

Yass lost, but that year he and his friends repeated variations of the strategy at horse and greyhound tracks around the country. Then they decided to turn their focus from a world of hundreds of thousands of dollars to a world of billions: Wall Street.

Four decades later, the firm he and his friends founded, Susquehanna International Group, is a sprawling global company that makes billions of dollars. Yass and his team used their numerical expertise to make rapid-fire computer-driven trades in options and other securities, eventually becoming a giant middleman in the markets for stocks and other securities. If you have bought stock or options on an app like Robinhood or E-Trade, there’s a good chance you traded with Susquehanna without knowing it. Today, Yass, 63, is one of the richest and most powerful financiers in the country.

But one crucial aspect of his ascent to stratospheric wealth has transpired out of public view. Using the same prowess that he’s applied to race tracks and options markets, Yass has taken aim at another target: his tax bill.

There, too, the winnings have been immense: at least $1 billion in tax savings over six recent years, according to ProPublica’s analysis of a trove of IRS data. During that time, Yass paid an average federal income tax rate of just 19%, far below that of comparable Wall Street traders.

Yass has devised trading strategies that reduce his tax burden but push legal boundaries. He has repeatedly drawn IRS audits, yet has continued to test the limits. Susquehanna has often gone to court to fight the government, with one multiyear audit battle ending in a costly defeat. The firm has maintained in court filings that it complied with the law.

Yass’ low rate is particularly notable because Susquehanna, by its own description, specializes in short-term trading. Money made from such rapid trades is typically taxed at rates around 40%.

In recent years, however, Yass’ annual income has, with uncanny consistency, been made up almost entirely of income taxed at the roughly 20% rate reserved for longer-term investments.

Congress long ago tried to stamp out widely used techniques that seek to transform profits taxed at the high rate into profits taxed at the low rate. But Yass and his colleagues have managed to avoid higher taxes anyway.

The tax savings have contributed to an explosion in wealth for Yass, who has increasingly poured that fortune into candidates and causes on the political right. He has spent more than $100 million on election campaigns in recent years. The money has gone to everything from anti-tax advocacy and charter schools to campaigns against so-called critical race theory and for candidates who falsely say the 2020 election was stolen and seek to ban abortion.

ProPublica has pieced together the details of Yass’ tax avoidance using tax returns, securities filings and court records, as well as by talking to former traders and executives. (The former employees spoke on condition of anonymity, with many citing a desire to avoid angering Yass.)

Through a spokesperson, Yass declined to be interviewed for this article. The spokesperson declined to comment in response to a long list of questions for Susquehanna and the firm’s founding partners.

Gregg Polsky, a University of Georgia law professor and former corporate tax lawyer who was retained by ProPublica to review Susquehanna’s tax records, said the tax agency may have more to scrutinize. The strategies revealed in Yass’ records, he said, were “very suspicious and suggestive of potential abuse that should be examined by the IRS.”

More than 35 years after he was booted from the racetrack outside Chicago, Yass still lives to gamble. Not just on horses, but on poker and on the market. He sheepishly admitted, in a podcast discussion, that he has even placed wagers on his children’s sports games.

Asked to describe his approach to trading at Susquehanna, Yass once reached for a poker analogy. “If you’re the sixth-best poker player in the world and you play with the five best players, you’re going to lose,” he said. “If your skills are only average, but you play against weak opponents, you’re going to win.”

That philosophy along with, Yass freely admits, a lot of luck, has made him a billionaire many times over.

Compared to many of his fellow billionaires — he’s richer than Hollywood mogul David Geffen, retail brokerage king Charles Schwab and “Star Wars” creator George Lucas — Yass doesn’t seem particularly interested in the trappings of extreme wealth.

Yass and his wife, Janine, raised four children in the leafy college town of Haverford, on the Main Line outside of Philadelphia. Their large but unremarkable house could easily be the home of a successful doctor rather than one of the richest men in the country. In his quarter-zip pullover sweater, Nikes and no-nonsense rimless glasses, he’d be impossible to pick out of a crowd at the suburban country club where he plays golf.

If Yass collects expensive art or maintains a megayacht, he has managed to do so in complete secrecy. What comes closest to an identifiable trophy asset is a house in the ultra-exclusive Georgica Association beach neighborhood of East Hampton on New York’s Long Island. Even that property, purchased for $12.5 million in 2005 and held through an LLC, is in an area known as “bucolic and understated.”

Those who have worked with Yass say he lives less for spending money than for the competition of the market and the thrill of taking calculated risk. Yass softens any impression of ruthlessness by deploying a practiced humility and comedic timing. “Some people like art history,” he once explained, “I like probabilistic analysis.”

Yet when it comes to his philosophical outlook, he eschews the jokes. He speaks of capitalism in religious terms. Making new markets, he likes to say, is a “mission from God.”

Like many religious stories, his begins with a conversion experience. Born in 1958 to two Queens CPAs, Yass said reading the economist Milton Friedman’s “Capitalism and Freedom” as a young man delivered him from an early flirtation with socialism.

By the time Yass graduated from the State University of New York at Binghamton in 1979, he was already captivated by trading. (His father had also helped nurture Yass’ love of horse racing by taking him to local tracks to see harness racing, according to Forbes.) Yass’ college thesis weighed whether the budding market in stock options could be justified as socially useful. “I concluded that it should exist,” Yass later cracked. “I got a B.”

After college, he moved to Las Vegas for a year and a half to play poker professionally. Then he returned to the East Coast and settled in Philadelphia, where he began trading options. The previous decade had seen a burst of academic interest in the financial instruments, including a pioneering model of how to more accurately price them. Yass later called the model, and its broader implications for how to make mathematically sound decisions, “the most revolutionary idea in a long, long time.”

A share of stock is a relatively simple concept: It’s a small ownership stake in a company. An option, by contrast, is a contract that confers the right to buy or sell a given stock at a particular price and time in the future.

Options attract mathematically minded traders since a complex set of variables, including the underlying stock price, volatility, time and interest rates, determine how much one of the contracts is worth.

Options are a versatile tool. They can appeal to the risk-averse: Traders can use them as insurance to guarantee they will be paid at least today’s price when they sell in the future. They are also useful to the risk-embracing — gamblers who want to place outsized bets on how a stock will perform. (Here’s how a speculator would use an option: In early June, shares of Netflix were trading at below $200. If the speculator thinks the company’s fortunes will improve dramatically this summer, they could pay just $4.50 each for options to buy the stock at $250 in mid-August. If the stock soars over that figure, they could make a mint.)

In options Yass found more than a financial instrument. He found a way to view the world. Everything — each decision, each interaction — can be judged based on how much it will cost in money, time or negative consequences and compared with the reward. Then action is taken or avoided accordingly. To Yass’ way of thinking, it’s always worth paying $19 for a 20% chance to win $100 but it’s never worth $21.

Along with his college friends, Yass founded Susquehanna, named after the river that connects Binghamton to Pennsylvania, in 1987. The firm benefited from explosive growth in options markets. Yass later played it down to the Philadelphia Inquirer: “We got lucky being in the right place at the right time.”

One of Susquehanna’s landmark moments — involving perhaps both skill and luck — occurred soon after the firm launched: the Black Monday stock market crash on Oct. 19, 1987. Thanks to an option bet that would pay out if stocks went down, Susquehanna was one of the few firms that made money on one of the worst days in stock market history.

From early on, Yass cultivated Susquehanna’s brand as a home for the biggest brains in finance, hiring Ph.D.s and top students. But the firm wasn’t just looking for raw IQ points. It also wanted instinct. It held poker tournaments to teach traders the idea that taking the measure of your opponents is as important as understanding the odds.

The Binghamton buddies ran a freewheeling office full of arguments and gamesmanship. The office had Super Bowl pools and an officewide lottery. Everyone bet on everything. One time, as recounted in Philadelphia magazine, traders bet on whether Yass could name the last Plantagenet king of England. They called Yass. He spat out “Richard III” and then, according to a witness, yelled, “Get back to work!” But he liked the hijinks.

Still, the firm had an inside vs. outside mentality. If you weren’t with the firm, you were the enemy. When traders left to join a competitor, Susquehanna often sued them for allegedly violating non-compete clauses. Susquehanna stood out for its aggressiveness in trading even by the standards of Wall Street. “If he thinks you’re dumb, he’s betting against you,” one former Susquehanna trader said of Yass. “That’s what makes his blood flow.”

Susquehanna developed a specialty in arbitrage, or finding low-risk profit opportunities in mismatched prices of securities, like stocks or bonds. An early adopter of computers to measure risk and test trading strategies, the firm flourished.

In addition to making his own bets, Yass built his firm into one that stands at the very center of the market and takes bets from other traders. On Wall Street, this job is known as market making.

At its simplest, making a market means offering to buy or sell a thing. The jewelry shop on the corner that will sell you a gold ring and has a “We Buy Gold” sign in the window is making a market in gold. If the store buys a gold coin from a customer for $300, then sells it for $320 to the next person who walks in, the store has made a quick $20.

Susquehanna does the same thing, but with securities. Running a market making firm isn’t always as easy as quickly matching a buyer and a seller. A market maker is expected to post its prices and buy and sell to all comers. If a particular stock has more sellers than buyers, the firm might find itself holding too much, exposing the market maker to losses if the stock price drops. It’s a business that thrives when there’s lots of trading volume but can be dangerous if markets crash.

The market making business in stock options, Susquehanna’s specialty, requires juggling a huge number of trades while constantly keeping an eye on all the various bets to make sure that the firm is protected from unexpected market moves.

In 1996, the year Yass turned 38, he made $71 million, tax records show. By then, the firm was employing hundreds of people. Not long before, Susquehanna staff had gathered in Las Vegas for an annual company celebration. Traders brought their families. The firm’s employees watched the Kentucky Derby together. A Marilyn Monroe impersonator interviewed Yass’ father with some tame double-entendres. The highlight was a skit with a junior trader performing as “Jeff Yass Gump,” after Forrest Gump. “Momma always said I was like the other kids,” the trader said. “But the other kids, they went to Harvard and Yale and the University of Pennsylvania and I said: ‘Momma, why am I at the SUNY Binghamton?’ She said it was because I was special.” The crowd roared, Yass the loudest of all.

Despite losing some star traders in the late 1990s, Susquehanna continued to produce massive profits. Yass and the other co-founders managed to keep their enormous wealth a secret. Even by 2005, when Yass had collected at least $1 billion of lifetime income, he was nowhere to be found in the Forbes list of the richest Americans.

That’s in part because Susquehanna is privately held and trades only its own money, meaning it doesn’t have to publicly disclose much about its business. Like many financial firms, Susquehanna itself is not a single company but a complex and shifting web of legal entities whose profits flow to Yass and a small set of partners.

It has been a remarkably consistent profit machine for the partners, except in 2008, the year of the global financial crisis. Yass alone lost $470 million that year, tax records show. Former Susquehanna traders believe the firm risked going out of business. The danger the firm faced “sent chills through everyone,” said one. Like other big trading complexes that did huge business with investment banks, Susquehanna benefited from the massive federal bailout of Wall Street, which propped up the giant firms that were among its biggest trading partners.

Yass, the free market true believer, now owed the survival of much of his fortune to the U.S. government. On a personal level, Yass also received an extra bonus from the government: a $2,000 child tax credit because he reported losing money that year.

Susquehanna quickly bounced back to profitability. In recent years it has supplanted major banks as one of the firms that sits in the middle of massive daily financial flows in stock and other markets. A Bloomberg profile in 2018 reported that Susquehanna trades 100 million exchange-traded fund shares daily. The firm is a prominent player in cryptocurrencies like bitcoin and, in a throwback to Yass’ origins, the exploding business of sports betting. Susquehanna has also branched out into venture capital. One of those investments came through spectacularly: a large stake in ByteDance, the Chinese company behind the social media app TikTok.

By the 2010s, Yass had become one of the richest Americans. But his ultralow profile meant that almost nobody knew that. At least two of Susquehanna’s other co-founders, Arthur Dantchik and Joel Greenberg, have each made billions of dollars themselves, according to ProPublica’s analysis.

Yass hit a new milestone in 2012, pulling in more than $1 billion in a single year, according to tax records; by 2018, his income was $2 billion. In the six years ending in 2018, Yass had the sixth-highest average income in the entire country, according to IRS data.

Court filings and ProPublica’s analysis of tax records suggest that, as of 2018, Yass owned around 75% of Susquehanna, with co-founders Dantchik owning around 19% and Greenberg around 3%. (Greenberg retired in 2016.)

Yass was finally added to the Forbes list last year. The magazine put his worth at $12 billion, which would make him the 58th-richest American. ProPublica estimates his true wealth is likely at least $30 billion — based solely on his income over the decades and stake in ByteDance — which would place him in the top 25.

On a Friday afternoon in April 2010, a Susquehanna trader in Pennsylvania emailed his counterparts at Credit Suisse to make a big bet in the stock market. The email instructed the Swiss bank to buy about $70 million worth of shares in some of Switzerland’s biggest companies on Susquehanna’s behalf.

Three minutes later, the trader sent out a second email, this time to Morgan Stanley. He placed a second bet, now wagering against the exact same stocks in the exact same amounts he’d just ordered from Credit Suisse.

The payoff from such a trade might seem to be nothing at all. But there was a winner and a loser. The winner was Susquehanna. The loser was the U.S. government: Susquehanna had managed to slash its tax bill through the trade. The emails come from an ongoing U.S. Tax Court case filed in 2020. There are rules designed to block clever traders from using offsetting bets to conjure tax savings, and the IRS argues Susquehanna broke them. (More on that case later.)

The firm’s willingness to push the boundaries of tax law is not surprising to people who know Yass and his partners. One former Susquehanna executive recalled Yass acknowledging using a trading strategy in which a main goal was not to make profitable trades, but to avoid taxes. Taxes, according to Yass’ former colleagues, are an obsession for the billionaire. As one former employee put it, “They hate fucking taxes.”

It doesn’t matter how seemingly trivial it is. Susquehanna once petitioned the state of Pennsylvania to demand “a refund of taxes paid on repairs to ice machines.” The petition was denied.

Indeed, the firm has a habit of shaping deals that slash its tax bill and then daring the IRS to intercede. Sometimes, the agency successfully challenges them, as when Yass and his two main partners were hit with a total of $121 million in back taxes in 2019. That was the single biggest such payout in ProPublica’s database of IRS records, which includes thousands of audits of the wealthiest people in the country. Susquehanna paid only after losing a long-running battle with the agency, one the firm appealed all the way to the Supreme Court.

Despite periodically tripping IRS wires, the firm’s aggressiveness seems to have paid off. Susquehanna’s tax avoidance has gone on for years, resulting in a strikingly low tax rate for Yass and his partners, according to ProPublica’s analysis.

The strategy behind that trade back in 2010 is key to understanding how they’ve done it. Similarly to how Susquehanna has taken advantage of small differences in prices of options or stocks, it has found ways to exploit a gap in tax rates to save hundreds of millions of dollars in taxes every year.

For someone like Yass, the U.S. system offers an almost irresistible proposition. If you earn the wrong sort of income — the kind that comes from a short-term trade — you’ll pay a relatively high tax rate. But if you earn the right kind — gains on long-held investments — you’ll pay half as much in taxes.

But what is considered “long-term” involves a bright, arbitrary line. Hold a security for less than 366 days, and you are on the wrong side of that line.

The result is that by the arithmetic of the U.S. tax code, $100 made from a sale on the 365th day is worth around $60 after taxes. And $100 made on the 366th is worth around $80.

Short-term, high-frequency traders like Susquehanna often hold securities for less than 365 seconds. As the company itself put it in one recent court filing, the firm “trades securities, commodities, and derivatives, seeking to earn returns from short-term appreciation and arbitrage profits.” This has been the firm’s consistent self-description. Back in 2004, a staffer was more frank in testimony: “We are not, by our nature, into holding stocks.”

With such an approach, long-term gains should be forever out of reach.

And yet, Yass and his partners have managed, year after year, to report that the vast majority of their net income came in the form of long-term capital gains. In several recent years, 100% of their income was taxed at the lower rate.

How do they do it?

One strategy, in simplified form, works like this: Make two bets that should move in opposite directions. Think of, say, both betting on and against Coca-Cola’s stock. Towards the end of the year, one bet will be up, and one will be down. At 365 days, the last day a trade is considered short-term, sell the one that’s down. A day later, sell the one that’s up.

Of course, if you consider the trade as a whole, it makes no money. But that isn’t the point. You’ve found a risk-free way to generate two valuable commodities: short-term losses and long-term gains.

On their own, these losses and gains aren’t of much use. But to someone like Yass, who separately generates an enormous pile of short-term gains each year, they work a kind of magic.

That’s because of how taxes are calculated. Short-term and long-term results are accounted for in separate buckets: Short-term losses are applied first to short-term gains. So the losses from the Coke trade reduce the existing pile of short-term gains. The money made from the Coke trade, meanwhile, goes in the long-term bucket.

In the end, the trader has essentially transformed short-term gains into long-term gains, the type taxed at the special lower rate. From 2003 through 2018, the difference between the two rates ranged from 17 to 20 percentage points. So, for every $100 run through this process, the trader would net from $17 to $20 in tax savings.

So why isn’t everyone using this strategy?

Because as laid out here, it would be illegal.

For decades, traders have devised strategies that looked something like the Coke trade, known as a “straddle” because the trader is taking both sides. Over the years, Congress passed laws and the IRS imposed intricate rules to stop them, taking away the tax benefit of simultaneously betting for and against the same stock.

And yet, Yass and his partners built a machine that produced much the same result.

Since 2011, IRS records show, a partnership called Susquehanna Fundamental Investments has been the source of the majority of long-term gains for Yass and his partners. Every year, it channeled hundreds of millions in long-term gains to them, while also providing hundreds of millions in short-term losses.

Year after year, the gains and losses rose and fell roughly in tandem, as if one were a near reflection of the other. In 2015, for example, Susquehanna Fundamental produced $774 million in long-term gains and $787 million in short-term losses for Yass. In 2017 it was $940 million in long-term gains and $902 million in short-term losses.

Regulatory filings give a glimpse of the fund’s trading.

Susquehanna Fundamental has to disclose a snapshot of certain holdings with the Securities and Exchange Commission a few times each year, though many types of trades are exempt from disclosure.

Over several years, the fund’s disclosed positions resembled a complex version of the Coke trade. Instead of betting for and against a single stock, the firm bet for and against the entire market.

Susquehanna Fundamental held billions of dollars of individual stocks such as Google, Wells Fargo and, as it happens, Coca-Cola. These stocks were among the largest companies in the S&P 500 index.

Meanwhile, the fund also held a large bet against the S&P 500. In essence, it held a bet against many of those exact same stocks.

On its face, the fund actually lost money for Yass: Over eight years, it registered $5.4 billion in losses against $5 billion in gains — a net loss before taxes. But by transforming the tax rate on so much income, it delivered $1.1 billion in tax savings, and Yass came out way ahead.

It’s not clear whether the IRS has ever challenged the firm’s trading inside Susquehanna Fundamental Investments.

But the trading pattern has similarities to the 2010 Swiss stock trades, which involved betting for and against the exact same stocks. The IRS deems those to have been illegal under tax law.

Those trades were part of a larger deal worked out by Susquehanna and Morgan Stanley that called for the Philadelphia firm to buy $1.4 billion of the stocks and simultaneously bet against them, court records show. (Morgan Stanley declined to comment.) Over the next three years, the deal kicked out at least $365 million in low-rate income to the firm, while generating massive losses that could be used to wipe out other high-rate income, according to the IRS.

When IRS auditors scrutinized the deal, they found that Susquehanna had violated rules against betting for and against the exact same stocks. The agency demanded the firm pay tens of millions of dollars in back taxes.

Yass and his partners refused, arguing that the firm had broken no rules, and sued the IRS in U.S. Tax Court in 2020. They asserted that the deal was supposed to be profitable and wasn’t primarily intended to avoid taxes. But the firm also acknowledged the deal was tailored with an eye to “tax efficiency.” The case is still pending, with Susquehanna currently resisting requests to turn over more documents.

Susquehanna’s ability to manufacture the right kind of income has helped Yass and his partners minimize their taxes for decades. Since 2001, Yass hasn’t paid over 20% in a single year. In 2005, a year when he made what was for him the modest sum of $66 million, he paid $0 in federal income tax.

For Yass’ primary competitors, the story is far different. Citadel and Two Sigma are both huge firms that, like Susquehanna, do a mix of lightning-fast trading and market making. The heads of these firms, like Yass, reported incomes larger than almost anyone else in the country from 2013 to 2018.

But the tax returns of these Wall Street titans — Ken Griffin from Citadel, and John Overdeck and David Siegel from Two Sigma — have no mystifying source of low-rate income.

They also differ from Susquehanna in another telling respect. These firms voluntarily classify their trading activity as ordinary income, according to ProPublica’s analysis of tax records. Doing this makes sense for a firm that specializes in short-term trading and doesn’t expect to generate many long-term gains. That’s why many high-frequency firms make this “Section 475 election,” as it’s called in the tax jargon. If Susquehanna elected to treat its trading this way, its ability to generate long-term gains would be constrained.

Susquehanna also stands apart in how its taxes are prepared, ProPublica’s records show. Unlike his billionaire peers, Yass does not have his tax returns prepared by outside accountants. Instead, they’re prepared in-house at Susquehanna. Avoiding an outside accountant can offer more leeway in filing returns that test the boundaries of the law and might be challenged by the IRS later on, experts say. Several former employees told ProPublica that details of the firm’s tax strategy are closely guarded, even inside the company.

From 2013 to 2018, Griffin, Overdeck and Siegel paid average income tax rates ranging from 29% to 34%. (Representatives for the three men declined to comment.) Yass averaged 19%. ProPublica estimates that if Yass’ tax returns had resembled those of his competitors, he would have paid $1 billion more in federal income taxes during this period alone.

Yass does have one peer who achieved even lower tax rates and did so for years. Billionaire Jim Simons is one of the founders of Renaissance Technologies, one of the premier hedge funds known for high-frequency trading. His rates were often in the single digits between 2009 and 2018, never exceeding 14%. One reason Simons paid so little are deductions from charitable donations, averaging hundreds of millions of dollars each year; Yass doesn’t give nearly as much to charity. But another reason was Renaissance’s ability to create long-term gains over a decade.

That, however, didn’t last. A 2014 congressional investigation and IRS audit concluded the Renaissance scheme to generate such gains was illegal. Simons himself ultimately paid the IRS at least $670 million to resolve the case. Collectively, fund executives and investors paid an undisclosed amount, reportedly in the billions, in back taxes and penalties. A spokesperson for Simons declined to comment.

Having slashed his income tax bills, Yass has already taken steps to protect his fortune from the government for years to come.

He created special trusts designed to sidestep the estate tax when passing money to heirs at death, court records show. In using these grantor retained annuity trusts, or GRATs, Yass joins dozens of other billionaires, as ProPublica has reported.

That suggests that Yass’ adult children, two of whom work at Susquehanna, stand to someday inherit multibillion-dollar fortunes — tax-free.

Over decades of TV appearances and speeches promoting his libertarian gospel, Milton Friedman often liked to say he was “in favor of cutting taxes under any circumstances and for any excuse, for any reason, whenever it’s possible.” Friedman died in 2006. Today, Yass, who reveres the economist, is trying to bring Friedman’s ideas to fruition.

Yass has not only worked assiduously to lower his own taxes but has poured millions into political efforts to eliminate them for his class. In recent years he has given $32 million to the anti-tax stalwart Club for Growth. This money paid for TV ads attacking candidates who were seen as wobbly on Friedman’s tax-cuts-anytime-anywhere philosophy.

In Pennsylvania, where Yass is the richest person in the state and a kingmaker in local politics, his favored candidates have shaped tax policy. He is a longtime financial patron of a Democratic state senator, Anthony Williams, one of the creators of a pair of tax credits that allow companies to slash their state tax bills if they give money to private and charter schools. Susquehanna is, in turn, a major user of the tax credits. (Williams did not respond to requests for comment.)

The programs limited the state tax credits a single company could receive, but Yass and the others found a way to sidestep the limits. Yass, Dantchik and Greenberg simply applied for the tax credits through individual companies each had formed, the Philadelphia Inquirer reported in 2015. In all, the credits have saved Yass and the others at least $53 million in state taxes, records show.

Yass’ views on taxes, along with another stance inspired by Friedman, school privatization, seem to have informed his shifting opinion of Donald Trump.

Yass had opposed Trump during the 2016 Republican presidential primary, instead donating large sums to Rand Paul of Kentucky, the de facto leader of the party’s libertarian wing, and to Libertarian Party nominee Gary Johnson.

A week after Trump won the presidency that November, Yass took the stage at a theater in Philadelphia. Even though Trump had not been his candidate, Yass seemed to relish the long-odds election win, joking that those who “didn’t like Tuesday’s results” could move to Canada.

He used the rest of his remarks at the event, part of a local TED Talk-style series, to promote his passion for charter and private schools and attack Philadelphia teachers. “All we ever hear about is how underpaid they are and how abused they are,” Yass said. “Well, the shocking fact is that the average school teacher in Philadelphia with benefits makes $117,000 a year.” Yass acknowledged that a large chunk of that figure was from pension and health care costs. (That year, Yass made $1.26 billion, before benefits.)

Over the next four years, Trump delivered both a historic tax cut for the rich and an education secretary who was a champion of charter schools.

Yass has since backed a range of pro-Trump candidates. In Pennsylvania, he has poured money into this year’s Republican effort to take the open gubernatorial seat, which many expect, if successful, will lead to an abortion ban in the state. The Club for Growth also backed a losing candidate for the state’s open U.S. Senate seat, Kathy Barnette, whose campaign centered on her hard-line opposition to abortion, even in cases of rape. Yass is the second biggest donor to the Club (which did not return ProPublica’s requests for comment).

He is also the largest donor to the Rand Paul-affiliated Protect Freedom PAC, giving $2.5 million of his more than $12 million in recent donations just days after the 2020 election. The group’s website says of Democrats: “Of course, they stole the election.”

Yass is looking to harness discontent with public schools during the pandemic to push privatization of the system. He has given $15 million as the sole funder of a political action committee, the School Freedom Fund, that says “school closures, mask mandates, critical race theory, and more” have created “a unique opportunity to promote School Choice as the structural solution to dramatically improve education in America.”

If Yass came to politics motivated by his libertarian ideology, he now has an acute material reason — beyond taxes — to have a voice in Washington.

Late in the Trump administration, Susquehanna’s prize investment came under threat. President Trump announced on July 31, 2020, that he was considering banning TikTok in the United States. (Backers of the ban cited national security concerns over Americans’ private data being controlled by the Chinese firm behind the app, ByteDance.) Susquehanna’s multibillion-dollar stake in ByteDance accounts for a major part of Yass’ fortune.

There’s no record of Yass having given to Trump before. But on Aug. 4, 2020, just a few days after the president’s TikTok announcement, Yass gave $5 million to the Club for Growth. Two days later, the group deviated from its normal practice of funding congressional races and announced an ad campaign in the presidential race: $5 million against Joe Biden. The group didn’t mention Yass, but the ads attacked Biden on Yass’ pet issue, charter schools. Later that month, Yass gave the group another $5 million, and more ads ran against Biden.

At the same time, Trump and other administration officials were personally involved in trying to broker a deal to avoid finalizing the TikTok ban. At one point in September, Trump publicly announced his support for a deal in which U.S. companies would buy stakes in ByteDance and a new board would be formed. Among the proposed members of the board: Dantchik, Yass’ partner at Susquehanna.

It’s not clear if Yass or Dantchik talked to the White House about the deal, which ultimately fell through. Courts later blocked the proposal to ban the app.

Yass hasn’t spoken much publicly about how he thinks about his engagement in politics. A rare glimpse came after the Jan. 6 riot, when a Philadelphia political activist named Laura Goldman emailed Yass to question his donations to the Club for Growth. One of the candidates the group backed, Sen. Josh Hawley, R-Mo., had objected to certifying the presidential election results just days earlier.

“To be clear — I don’t think the election was stolen,” Yass responded in a Jan. 15, 2021, email, first reported by the Guardian. “I gave the club money a year ago. Do you think anyone knew Hawley was going to do that? Sometimes politicians deceive their donors.”

Yass appears to have overcome any doubts about the Club for Growth, which has continued to back candidates who say the election was stolen.

Since he sent that email, he has given the group another $5.5 million.