Marks argues outcomes cannot determine decision quality because randomness causes good decisions to fail and bad ones to succeed.
“you can't tell from an outcome whether a decision was good or bad. It's very important. Most people don't understand this. Totally counterintuitive.”
Marks says good decisions fail and bad decisions succeed frequently due to randomness in investing.
“good decisions fail to work all the time. Bad decisions work all the time. The investment business is full of people who are, quote, right for the wrong reason.”
Marks disputes the notion that success is never accidental, asserting that accidents happen regardless of preparation.
“I couldn't disagree more. There are happy accidents. There are unhappy accidents. Now, you know, people say luck happens when preparation meets opportunity.”