Well, the 90% drawdown just tells you how much risk he was taking. Just matter of time till his account is toast.
You got that right. Without risk management, you cannot succeed in the stockmarket. It just takes one big whack to put you out of business. Even buy and hold entails huge risks. Take CSCO in 2000 was as high as $100.00, today August 14, 2018 is worth $44.00. So, 18 years later you have lost 56% and still waiting to just breakeven! I know because I had CSCO then, and had 200 shares at a $100 when I started out and lost a good chunk of those monies! I sold out much earlier after that huge loss!