Mark Douglas Cause of Death: How the Trading Psychology Guru Left a Lasting Legacy

Mark Douglas was a renowned trader, investor, author, and coach, who pioneered the concept of trading psychology. He wrote several influential books on the topic, such as The Disciplined Trader and Trading in the Zone, and helped thousands of traders improve their performance and mindset. He passed away unexpectedly on September 12, 2015, at his home in Scottsdale, Arizona. He was 67 years old. The cause of his death was not publicly revealed by his family, but some sources speculated that he suffered a heart attack. In this article, we will pay tribute to Mark Douglas, his life, his career, and his legacy.

A Passionate and Driven Athlete

Mark Douglas was born in 1948 in Montana, to Donald and Jay Petro. He graduated from Niskayuna High School in 1981, and from Boston College in 1985, where he studied business administration. He also received his MBA from the University of Chicago.

Mark was a passionate and driven athlete, who excelled in various sports, especially running, skiing, and cycling. He was a cross-country and alpine ski racer, who became an NCAA All-American. He also competed in triathlons and amateur cycling, winning several national and international titles. He was known for his endurance, strength, and determination, as well as his humility and sportsmanship.

One of his most remarkable achievements was winning the 24 Hour Endurance Mountain Bike World Championship in September 2014, just three months before his death. He completed 18 laps of a 10-mile course, covering a total of 180 miles and 27,000 feet of elevation gain. He beat his closest competitor by more than an hour, setting a new record for the event.

A Successful and Generous Investor

Mark Douglas was also a successful and generous investor, who founded and ran Bay Hill Capital Management, a financial management and consulting firm based in Duxbury. He specialized in hedge funds, private equity, and venture capital, and had a keen eye for spotting and supporting promising businesses and entrepreneurs. He also taught graduate classes at Boston College, sharing his knowledge and experience with aspiring students.

Mark was not only interested in making money, but also in giving back to the community and helping others. He was a philanthropist, who donated to various causes and organizations, especially those related to children, education, and health. He was also a mentor, a friend, and a leader, who inspired and supported many people with his generosity, wisdom, and kindness.

A Devoted and Loving Family Man

Mark Douglas was a devoted and loving family man, who married his soulmate and best friend, Leah Conti, in 1990. They had three children, Christian, Grace, and Ben, whom he adored and cherished. He was also a proud and caring grandfather to three grandchildren, Carter, Charlotte, and Cooper. He was a dedicated and supportive husband and father, who always put his family first. He was also a loyal and fun-loving son, brother, and uncle, who enjoyed spending time with his relatives and friends.

Mark loved to travel, read, cook, garden, and play games with his family. He was also a faithful member of The Church of Jesus Christ of Latter-day Saints, who served in various callings and had a strong testimony of the gospel. He was a compassionate and optimistic person, who faced challenges and trials with courage and grace. He was a role model and a hero to his family, who admired and respected him for his character and values.

A Pioneer and a Guru of Trading Psychology

Mark Douglas was a pioneer and a guru of trading psychology, who revolutionized the way traders think and act in the market. He started trading in 1978, but soon realized that his lack of discipline and confidence was costing him money. He almost lost everything in the market within nine months of moving to Chicago in 1981, where he worked as a broker with Merrill Lynch at the Chicago Board of Trade.

But his mistakes also taught him a lot. He began to study the psychology of trading and developed his own methods and principles. He started coaching in 1982 and traveled around the world for over 25 years, teaching traders how to gain discipline and confidence. He founded Trading Behavior Dynamics INC. in Chicago, a company that provided educational trading programs. He was also a financial consultant for financial trading institutions and investment banks, such as the Chicago Board of Trade, New York Board of Trade, Citibank, Deutsche Bank, and more.

Mark Douglas wrote several books on trading psychology, which became bestsellers and classics in the field. His most famous books are The Disciplined Trader: Developing Winning Attitudes, published in 1990, and Trading in the Zone: Master the Market with Confidence, Discipline, and a Winning Attitude, published in 2000. In these books, he explained the importance of having a trader’s mindset, which is based on four fundamental truths:

  • Anything can happen in the market.
  • You don’t need to know what is going to happen next to make money.
  • There is a random distribution between wins and losses for any given set of variables that define an edge.
  • An edge is nothing more than an indication of a higher probability of one thing happening over another.

Mark Douglas also taught traders how to overcome their fears, biases, and emotions, and how to develop a consistent and profitable trading system. He emphasized the concepts of risk, probability, and expectancy, and how to use them to manage trades and money. He also showed traders how to cultivate a positive and empowering belief system, and how to align their goals and actions with their trading plan.

Mark Douglas’s books and teachings have influenced and helped countless traders around the world, who regard him as a master and a mentor. His insights and wisdom are timeless and universal, and his legacy lives on in the trading community.


Mark Douglas was a remarkable man, who lived a full and meaningful life. He touched the lives of many people with his talents, achievements, and generosity. He will be dearly missed by his family, friends, and all who knew him. He leaves behind a legacy of excellence, service, and joy. We express our condolences to his family and hope that they will find comfort and peace in the memories of Mark and the promises of God. As Mark himself said, “The road to success is not a destination, it’s a process.”