Mark Douglas
Trading psychologist and coach (1948–2015). Started trading in 1978 while running an insurance agency in Detroit; moved to Chicago as a Merrill Lynch broker at the CBOT, blew up within nine months. Founded Trading Behavior Dynamics (1983) and spent decades teaching seminars and one-on-one coaching for floor traders, CTAs, and retail speculators.
Author of The Disciplined Trader (1990, seven years in draft) and Trading in the Zone (2000). His contribution is not market analysis but mental analysis — installing beliefs that let traders operate in unlimited, uncertain environments without fear or recklessness.
Core claim
Life skills (be right, avoid pain, plan outcomes) misfire in markets. Consistent winners share a probabilistic mindset: they don't need to know the next tick, accept risk before entry, and treat each trade as a unique draw from a distribution — then execute every edge in sample.
Influence in this wiki
Douglas sharpens the trading cluster where Livermore taught reversed impulses, CFI taught vocabulary, and Kahneman/Taleb taught bias. He is the dedicated bridge between process (decision-quality-vs-outcome) and real-time execution (trading-psychology).