Investor shares how three standard deviation move wiped out 90 percent of portfolio
"During my first year of trading, I experienced my first blowup where I was playing this game. In other words, I was placing trades that had a very, very high probability of success, and therefore I made a little bit of money on each trade. Because I looked at what I thought the odds were or what the statistics said the odds were, I said, 'Look, my probability or my odds of me losing on one of these trades is so small that I'm comfortable executing a ton of these trades and taking on more and more leverage.' So my portfolio in the beginning started to grow very, very quickly. I felt like a genius. But because I was playing a game where I couldn't control the odds, an unexpected move happened in the market, a three standard deviation move happened that I thought was virtually impossible, and I blew up. 90% of my portfolio on one trade that went the wrong direction."
About this episode
An investor who achieved over 36 percent compound annual growth rate over six years presents a contrarian guide to trading and investing by outlining seven guaranteed ways to lose money. The episode systematically explores destructive trading behaviors through the lens of inverse logic, arguing that understanding what causes failure illuminates the path to success. The speaker draws on personal experience, including a devastating first-year trading blowup where he lost 90 percent of his portfolio on a single leveraged trade after a three standard deviation market move. Key destructive behaviors identified include playing the house when you cannot control odds, going all-in on concentrated positions, focusing exclusively on profit potential while ignoring loss potential, entering positions without predetermined exit strategies, treating market odds as knowable probabilities, taking profits too aggressively, and never taking losses. The presentation emphasizes that losses are exponentially more powerful than gains, with a 90 percent loss requiring a 900 percent gain just to break even. The speaker challenges conventional wisdom about diversification, noting that holding 500 correlated stocks in an index fund does not constitute true diversification. He distinguishes between normal Gaussian distributions and power law Pareto distributions, arguing markets follow the latter where extreme events contain disproportionate impact and cannot be predicted using standard probability models. Throughout the episode, the speaker stresses that the inverse of each destructive behavior forms the foundation of successful investing, particularly the principle of cutting losses short while letting winners run, which he notes is repeated by history's most successful investors including Warren Buffett.
Key takeaways
- Investor lost 90 percent of portfolio in first year after three standard deviation market move destroyed leveraged high-probability trading strategy he believed was safe
- Losses are exponentially more powerful than gains requiring 900 percent gain to recover from 90 percent loss versus only matching percentage for small losses
- Markets follow power law Pareto distributions not normal distributions making odds and probabilities fundamentally unknowable unlike casino games where house controls odds
- Going all-in or heavily concentrating positions maximizes chance of portfolio-destroying drawdowns that require exponentially larger gains just to break even
- Taking profits aggressively eliminates possibility of small wins becoming large wins leaving portfolio performance driven entirely by inevitable large losses
- Never taking losses ensures every small loss has opportunity to become portfolio-destroying large loss since all large losses begin as small ones
- Successful investing requires inverse approach: control position sizing, focus on loss potential over profit potential, plan exits before entry, cut losses aggressively and let winners run