Every day, Curtis Carroll dons blue, state-issue jail garb. Every night, he sleeps in a cement cell. At 35, he has spent his entire adulthood behind bars, and there’s a possibility he’ll never leave: He’s serving a sentence of 54 years to life, for murder.

Among the inmates in California’s sprawling San Quentin State Prison, Carroll’s violent past is ordinary — but his present is anything but. In a place where physical toughness is the main way to earn respect, Carroll has built a following among his fellow prisoners by teaching them how to stay out of debt, draw up a budget — and pick stocks.

His friends call him “Wall Street.” In prison, that’s a compliment.

“From what I hear, I’m one of a kind,” he tells me when I meet him for an interview. A fast-talking man with a swagger befitting an A-list celebrity, Carroll greets me with an assured nod from behind black aviator sunglasses. Trim, short and clean-cut, he looks a decade younger than his years. “There is not a lot of people who’ve been doing what I’ve been doing, created what I’ve created,” he says.

That’s certainly true. At a time when financial literacy is barely taught even outside of prison, the classes Carroll conducts for fellow inmates represent an unusual effort to reach an undereducated population. (See also: What prison inmates learn about money.)

It’s an outcome that’s all the more unlikely because Carroll, by his own account, was illiterate when he got to prison. Now, he says, he reads the Wall Street Journal every day. He invokes Warren Buffett in conversation as one of his idols — and in homage to Buffett, one prison official calls Carroll “the Oracle of San Quentin.”

Carroll’s interest in investing goes back more than a decade, but his influence has grown since 2012, when he was transferred to this prison, a huge facility that hosts one of the country’s biggest prison education programs. Here, his experience and confidence have helped him turn dozens of people into “clients” who take his advice — including noninmates who volunteer at the prison.

San Quentin State Prison in California, where Carroll is teaching finance and stock-picking skills to fellow inmates while serving 54 years to life. Getty Images

“Everything he says is stuff you hear” from other financial talking heads, says Tom De Martini, an insurance agent who took classes from Carroll while volunteering. “But … to be doing it behind prison walls, it’s so impressive.” Another volunteer, photography professor Nigel Poor, says she invested in stocks for the first time after hearing Carroll. “I am 50; I wish someone had taught me this when I was 20,” Poor says. Fellow inmate Troy Williams says that most books about investing are “geared towards people with money,” but Carroll “has strategies for everyday, common people.”

Carroll says his lessons are designed to help his fellow inmates avoid hopelessness and crime. They’re also bucking a national trend: A Rand Corp. study published last year found that budget cuts were depressing the number of courses and students in many prison programs.

But Carroll is quick to add that his interests aren’t simply academic, or altruistic. “I go where the money goes — it’s always been that way,” he says. And the money for him, these days, is in stocks.

Or at least, it’s there in theory. It isn’t possible to independently assess Carroll’s track record: While he says he has brokerage accounts of his own, records that he shared with MarketWatch weren’t complete enough to gauge how well his investments have performed. As for his advice, it’s a mixed bag — some quite good, some risky and speculative, and most of it brand-new territory for a clientele that lives behind prison walls.

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Carroll says his family never had much money — they lived on welfare and bounced around from the streets to homeless shelters to churches to apartments in and around Oakland, Calif. He vividly remembers the day his mother got a windfall and bought him and his brother new bikes — and the day, not long after, when a local drug dealer took the bikes as repayment for his mom’s debts.

But Carroll befriended the dealer’s son — and eventually made friends with the dealer, too. He recalls wishing for a new pair of “red, bright-colored shoes” from LA Gear. While his mom couldn’t afford those coveted shoes, the drug dealer could.

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“He took me to the mall and bought me some,” Carroll says. “That is really when I started to, like, see the money as the means to everything — people with the money got the power.”

It didn’t take Carroll long to find a way to make money of his own. At a bowling alley where his mother worked as a waitress, an older man taught Carroll a grift: Curtis would play arcade games, distracting the alley owners while the man broke into the back of the machine and stole quarters. Soon, Carroll learned how to do the break-ins himself. “That became a part of my main source of income,” he says.

His newfound wealth was like a high to him, Carroll says: At some points, he’d have as much as $5,000, which he’d hide in a pillowcase buried in leaves in the woods, or in the wall at home behind his martial-arts plaque. At high school, “I used to take $5 bills and $1 bills and throw them into the crowd, just to see [people] go crazy.”

But as he got older, Carroll’s criminality caught up to him. His arcade-game robberies landed him in juvenile hall, he says. And in 1996, when he was 17, he and two friends were involved in the fatal shooting of a young man named Gilberto Medina Gil, in what police said was a botched robbery attempt. Carroll was accused of being the shooter; three years later, a jury convicted him of murder.

According to court records, a witness told police that Carroll told him, “I never thought I could pull a trigger like that.” Today, he says that his crime was “heinous”; he also says that he tried to send money to the victim’s family, something MarketWatch couldn't independently confirm.

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In one sense, the conversion from Curtis Carroll to “Wall Street” began before the jury found him guilty. Carroll, who used to pay other kids to do his homework for him, says he couldn’t read the court papers his lawyer put in front of him. “I don’t know if my lawyer ever knew” about his illiteracy, he says. Carroll is quick to add that illiteracy doesn’t excuse his crime. Still, he says, “Being illiterate is like being in a bubble. Being uneducated affects the way people move in life, it affects what they become in life.”

It took a while for that lesson to sink in. When he first got to prison, he was assigned a female reading tutor, and he had far more interest in her looks than her brains. “I wouldn’t mind going out there to look at a woman — I’m in jail,” he says. “I’m thinking I’m going to use the pages [as rolling papers] to smoke weed or something.”

Carroll says it wasn’t until he accidentally grabbed the business section of a newspaper — he was trying to get the sports section so that his cell mate could read it to him — that he had a light-bulb moment about reading. “An older [inmate] asked me if I played the stock market. I said ‘What’s that?’ And he says, ‘It’s a place where white people keep their money.’ ”

“The first thing I thought was, this has got to be where it’s at,” he says. “If I can read, I can find out about this business stuff. … Money is gonna be gotten somehow.”

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By the time Carroll had his epiphany, of course, the Internet was upending the way investors tracked the markets. For most inmates, access to the Internet is a rare privilege. So Carroll has taught himself the way someone might have done in the 1950s — by poring over stock quotes in newspaper financial sections. When we meet, he shows me stacks of binders filled with hundreds of pages of stock prices he’s copied over the years.

Most investors shy away from penny stocks because they’re hard to analyze; Carroll says he likes them because they’re cheap. Nigel Poor

Our interview took place in a shared library and classroom used by San Quentin’s education program, a room cluttered with books and mismatched office furniture. One wall is plastered with a list of stocks Carroll has picked, next to their prices at the time that he selected them. Carroll posted them on the wall, he tells me, to convince the prison’s public information officer, Lt. Samuel Robinson, that his stock picking “wasn’t just a bunch of shenanigans” aimed at defrauding fellow inmates. “In prison, you run across a lot of people who will con you, with visions of grandeur,” Robinson says. But he adds that once he got to know “Wall Street,” he came to trust him. “You’re not sitting down with a dummy,” he adds. “This guy is sharp.”

Since Carroll learned reading and investing simultaneously, it isn’t coincidental that, for him, stocks are about stories and emotions. When he’s thinking about investing in a stock, he says, he explains the basics of the company to other inmates, and gauges their reactions. “Psychology runs 70% of the markets,” he says. “Investors play follow-the-leader — if they didn’t, we wouldn’t have the 1%.”

Quoting Buffett — “Be greedy when others are fearful, and be fearful when others are greedy” — Carroll argues that the best opportunities to profit come when “people panic about stupid stuff.” His hypothetical example: Bill Gates dies in a plane crash and investors sell Microsoft stock, even though Bill Gates hasn’t been directly involved in the company’s operations in years. For Carroll, of course, that would be an opportunity.

The picks on the wall include Zynga ZNGA, +0.95% , Bank of America BAC, -0.55% and Facebook FB, -0.89% , which Carroll says he bought in December 2012. What the three stocks had in common at the time: Each was getting substantial bad press — most notably Facebook, thanks to investor malaise after its disappointingly muddled IPO. Those stocks are up 20%, 47% and 134%, respectively, since December 14, 2012; over that same stretch the S&P 500 is up 39%.

Carroll also stresses the importance of reading beyond financial publications. His magazine list includes some highly unlikely fare for a men’s prison, including Teen Vogue (great for insight into things that teens adopt first, like social media); PopStar! (to keep up with the entertainment industry) and Shape (for fitness innovations and products).

Stock picking is now, Carroll says, at the level of obsession: “ ‘Fun’ is, like, an understatement; it’s life.”

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For most inmates, though, stock picking isn’t life, or at least not real life.

Carl Takei, a staff attorney at the ACLU’s National Prison Project, says that it is generally legal for an incarcerated criminal to have assets outside of prison (though the state could seize assets as part of his sentence or in a separate proceeding). But he notes that most inmates aren’t earning money (at least not legally) to invest: If they’re investing at all, they’re most likely tapping into family funds or assets they had before they went to prison. And most have little or nothing to work with. Nearly 60% of the prison population reports a pre-arrest personal income of less than $1,000 a month (and 84% less than $2,000 a month), according to the Bureau of Justice Statistics; and nearly one in three reports being unemployed before going to prison.

Communication with banks and brokers can be difficult from behind bars, so inmates who do invest typically have someone on the outside make the investments for them, says Takei. (That’s what Carroll says he does; an outside contact through whom he says he invests didn't return calls requesting an interview.)

Plastered to the wall of our meeting room is a sheet of what he calls “the timeless rules of personal finance,” which are:

saving to build a nest egg and create an in-case-of-emergency fund; controlling costs by not allowing monthly expenses to exceed monthly after-tax income; not borrowing money you can’t repay; and diversifying your assets.

These eat-your-vegetables rules don’t seem to excite “Wall Street” as much as picking stocks does (one more way his experience mirrors the real Wall Street). But he says they’re a big component of the classes he teaches. Many prisoners spend any money they do have while behind bars, he says — mostly on unnecessary items like tobacco — and have nothing left over. Carroll has fellow inmates track their spending so they can see what’s coming in and going out. “I want them to have discipline when they get on the streets,” he says.

When he pivots from these financial-literacy basics to his ideas about playing the market, though, Carroll can wind up on shaky ground. Carroll is a fan of penny stocks, for example. He says he likes them because someone like an inmate, who doesn’t have a lot of money, can afford to buy several shares. But he doesn’t address the fact that these companies’ shares are often cheap because they’re financially shaky, and that investors in penny stocks are particularly vulnerable to fraud.

Carroll says he recommends specific stocks to inmates, and he uses a relatively simple questionnaire about basic financial statistics to help his students screen stocks. But he’s smoothly evasive when I ask him about which specific stocks he likes right now, changing the subject to broader topics.

The bigger issue, in the eyes of most investing pros, is whether inexperienced investors with modest means should be buying individual stocks at all. If you have only a small pot of savings, betting a large share of it on just a few stocks exposes you to more risk (violating Carroll’s own Rule No. 4, about diversification). Alex McAdams, personal-finance analyst for the consumer financial site NerdWallet, is one of many advisers who advocate index funds for lower-income investors. “Is it possible that you could have an insight [about a stock] that the rest of the market doesn’t recognize?” she asks. “Absolutely. Is it likely? Statistically, no.”

***

It’s telling, and maybe encouraging, that outsiders seem to take away different lessons from Carroll’s teaching than inmates do. Nigel Poor, the photography professor who is working on a project to help tell prisoner’s stories, said she was initially put off by Carroll’s obsession with money. But she found Wall Street’s classes “eye-opening” — and says that afterward she “realized I hadn’t really thought about my [financial] future.”

Thanks to Carroll’s class, Poor says, she bought her first stock last year: Hewlett-Packard HPQ, -0.99% , which has risen from about $23 per share when she bought it, to about $33 per share today (a return that beats the broader market). De Martini, the insurance agent, says that hearing Carroll talk about Twitter TWTR, +2.03% last September inspired him to buy it at its November IPO; he later “got out and made some profit on that.” (Twitter fell below its initial share price this April and has remained below it since then.) De Martini says he also made some money on American Apparel US:APP after hearing details about it in the class, but he cautions that in his opinion a lot of Carroll’s advice is “highly speculative” and risky.

For fellow inmate — many of whom didn’t graduate high school and haven’t had a “real” job in their lives — the message may be a simpler one, of empowerment. Troy Williams, who’s in prison for robbery, says he plans to apply what’s he’s learned in prison about budgeting and saving to his everyday life when he gets out. And Williams, like others, expresses admiration for Carroll’s chops as a teacher. “In most classes people drop out, but in his class everyone kept coming every week,” De Martini says. “They’re engaged.”

Carroll says he hopes that the engagement pays off — that inmates who might otherwise turn or return to crime upon their release can instead try to get their money in legitimate ways. “It’s another way to give them hope,” he says.

Will the Oracle of San Quentin get a chance to practice what he preaches? It’s hard to say. If he serves his full sentence, he’s not eligible for release until 2053. But in a recent email, Robinson, the prison official, told MarketWatch that because Carroll committed his crime as a juvenile, he could get a parole review as soon as the year 2020.

The Oracle’s response, filtered through Robinson: “He is excited about that.”

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