Mark D. Cook: The Ohio Farmer Who Beat the Market With His Own Indicator

Last reviewed: August 2026. Sources: Jack Schwager’s Stock Market Wizards and public records.

When Jack Schwager first met Mark D. Cook, it was at an industry conference where Cook was a fellow speaker — dressed in bib overalls. He was a farmer from a town of a thousand people in Ohio who had grown up working his father’s land and never stopped. He also happened to be one of the most consistent day traders in America, and the winner of a national investing championship with a return most professionals never see in a lifetime.

But the number that truly defines Cook is not his 563.8 percent championship year. It is the moment his trading account went from a healthy balance to hundreds of thousands of dollars below zero in a matter of days — and what he did over the next five years to climb out. Cook is the Wizard whose story is really about survival: how a catastrophic, self-inflicted loss became the foundation of a lifetime of discipline. He died in 2021, but the lessons he left are as sharp as ever.

The farmer who almost lost everything

Cook was born in 1954 and grew up on his father’s farm in rural Ohio, and he never lost his pride in those roots. Even after he had made millions trading, he still did manual labour on the land. He began trading in the late 1970s and, like almost every great trader, struggled badly at first.

Then came the catastrophe that shaped everything after it. In 1982 he sold naked call options on Cities Service and got caught in a squeeze. Selling naked calls means selling the right for someone else to buy stock from you at a fixed price while you hold no offsetting position — a trade whose potential loss has no ceiling. When the stock ran against him, his account collapsed from a positive $165,000 to a negative balance of roughly $350,000 in a matter of days. Across all the accounts he was responsible for, the cumulative loss came to around $815,000. He was, in plain terms, in negative net worth.

Most people never recover from that, financially or emotionally. Cook did, but it took him five years of relentless, disciplined work to climb back to even. Those five years, more than any winning trade, are what made him. He came out of them with a set of rules about risk and psychology that he would preach for the rest of his life.

The method: an indicator born in a farmhouse study

Working in his study, Cook developed the tool that became his signature: the Cook Cumulative Tick. It was built on the NYSE TICK — a measure of how many stocks on the exchange had just traded on a downtick versus an uptick — which Cook turned into a proprietary cumulative, overbought-oversold indicator designed to flag market reversals, drawing on the relationship between the S&P 500 and Treasury bonds. Every broker he described it to felt the opposite way about it, which only convinced him he had found a genuine edge. He credited the indicator with turning him into a millionaire trader.

Its first great test came in 1987. People assume his big year came from being short in the October crash, but Cook made most of his money in the bull market earlier that year. In May 1987 he saw what he considered a phenomenal opportunity in stock index call options: his cumulative tick was flashing extremely bullish readings at the same time that a decline in volatility had made option premiums unusually cheap. Two independent signals converged, and he acted.

His day-to-day style was high-frequency and probability-driven. Cook day traded S&P and T-bond futures and OEX options, sometimes putting on dozens of trades a day, and he was unusual in happily taking trades that offered only half a unit of reward for a unit of risk — provided the probability of winning was high enough. A setup that won seven times out of eight, making 3.5 units on the wins against one unit on the single loss, produced a solid net profit across the series. He was not hunting home runs; he was harvesting a small, repeatable edge over and over.

The defining lesson: hope is the most dangerous word

Out of the wreckage of the Cities Service trade, Cook distilled a rule he repeated for the rest of his career. Asked how he recovered, he told Schwager that “Hope should never be in your vocabulary.” The moment a trader catches himself hoping a losing position will come back, he said, is the exact moment to reduce size — not to wait, not to add, not to pray. Hope is the emotion that converts a small, survivable loss into an account-ending one.

Everything else in Cook’s discipline flowed from that principle. He cut his size when he was losing, to protect both his capital and the clear head he needed to trade his way back. He tracked his own performance obsessively and insisted that a trader must know his own numbers cold. The naked-options disaster had taught him, in the most expensive way imaginable, that the enemy was never the market — it was his own refusal to accept a small loss before it became a large one.

Where the Mind · Method · Money framework meets Cook

Method is the Cook Cumulative Tick and the probability-first day-trading style built around it: a proprietary reversal indicator, deep pattern recognition, and a willingness to take small-reward, high-win-rate trades that added up.

Money is the discipline written in the ink of a $350,000 hole. Never take a loss that can push you below zero, cut size the instant you start hoping, and shrink your exposure in a drawdown.

Mind is the resilience of the recovery and the honesty of the record-keeping. Five years to rebuild from negative net worth is not luck; it is relentless, self-aware, disciplined work — and the willingness to know exactly how you are performing at all times.

The honest counterweight

Cook’s story is genuinely inspiring, and precisely because of that it needs an honest reading.

Take the 563.8 percent. It is real and it was audited, but it was earned inside a one-year investing contest that rewarded concentrated, high-risk, short-term aggression. A contest return is a burst, not a sustainable long-run compounding rate, and the same aggression that wins a championship in one year can destroy an account in another. Cook himself is the proof: the appetite for risk that could produce a 563 percent year is the same appetite that produced a negative-$350,000 year. Do not read the championship number as something reproducible month after month.

The naked-options disaster is the heart of the story, and its clearest lesson is a warning. Selling naked options is picking up small, steady premiums in front of an occasional catastrophe, and Cook’s collapse from positive to deeply negative in days is exactly what that catastrophe looks like. He survived through extraordinary determination; most people who reach negative net worth this way never come back. His recovery is the survivor’s exception, not the expected outcome.

His indicator, too, demands caution. The Cook Cumulative Tick was proprietary and discretionary, read by a man with decades of feel for what a given number meant in context. A retail trader plotting the NYSE TICK has the data but not the judgment, and the divergence signals Cook is credited with calling look far cleaner in hindsight than they did in real time. And his half-unit-reward style, for all its positive expectancy, is psychologically merciless: winning small and often only works if you never once let a loser run, which is the very discipline most traders lack. One violated stop can erase a month of careful gains. Finally, this was a full-time professional’s game — dozens of trades a day, real commissions and slippage, hours of screen time — not a part-time approach a casual trader can bolt onto a day job.

What to actually take from Mark D. Cook

You do not need his indicator to absorb the most valuable things he taught.

First, never take on risk you cannot survive. Cook’s defining lesson was written in negative net worth. Know your true worst case on every position, and never place a trade that can put you below zero.

Second, treat hope as a sell signal. The instant you find yourself hoping a position recovers, reduce your size. Hope is the feeling that turns a manageable loss into a ruinous one, and recognising it is a genuine edge.

Third, cut your size in a drawdown. Like the best risk managers, Cook shrank his positions when he was losing, protecting both his money and his judgement.

Fourth, build a process you understand deeply and keep honest records. Cook developed his own indicator and tracked his results obsessively. You do not need his tool, but you do need a method you truly understand and numbers honest enough to show you the truth. And remember that resilience is a skill: blowing up is not always the end — refusing to learn from it is.

Frequently asked questions

Who was Mark D. Cook?
Mark D. Cook (1954–2021) was an Ohio farmer and professional trader profiled in Jack Schwager’s Stock Market Wizards. He developed the Cook Cumulative Tick indicator and won the 1992 U.S. Investing Championship with an audited 563.8 percent return.

What is the Cook Cumulative Tick?
A proprietary overbought-oversold indicator Cook built on the NYSE TICK — the count of stocks whose last trade was a downtick. He used it to identify market reversals, drawing on the relationship between the S&P 500 and Treasury bonds.

What was Mark Cook’s famous loss?
In 1982 he sold naked call options on Cities Service and was caught in a squeeze. His account fell from a positive $165,000 to a negative $350,000 in days, with roughly $815,000 in cumulative losses across the accounts he managed. It took him five years to recover.

What did Mark Cook win?
He was runner-up in the 1989 U.S. Investing Championship and won the 1992 contest with a 563.8 percent audited annual return.

What was Mark Cook’s trading style?
He day traded S&P and T-bond futures and OEX options, often making dozens of trades a day. He used his cumulative tick indicator for reversals and favoured high-probability trades, willing to take small rewards when the odds of winning were strongly in his favour.

What was Mark Cook’s rule about hope?
He said hope should never be in a trader’s vocabulary. The moment you catch yourself hoping a losing position will recover, that is the signal to reduce your size immediately rather than wait.

Which book features Mark D. Cook?
Stock Market Wizards: Interviews with America’s Top Stock Traders by Jack Schwager, in the chapter “Harvesting S&P Profits.”

Continue learning

• Bill Lipschutz — who shared Cook’s core discipline of cutting size the moment a trade turns against you.
• Stuart Walton — a fellow Stock Market Wizard who also fought his way back from near-ruin.
• Steve Watson — a fellow Stock Market Wizard whose edge, like Cook’s, was built on rigorous personal process.
• Mark Minervini — another Stock Market Wizard and champion trader who turned discipline into a record.
• Market Wizards (book review) — our breakdown of the Schwager series Cook appears in.
• The Mind · Method · Money framework — the lens we use to read every trader on this site.