You can't say "strategy A produced a better result than strategy B, therefore strategy A is a better strategy" based on a single example of someone using strategy A.
You have your example backwards.
We have a case of many many people using strategy A (index funds), and a single example of strategy B (Trump). And you can say that the strategy that worked lots of times is a better bet than the one that failed once. Strategy A is better in the limited sense that given our current information, it looks safer.
We have a case of many many people using strategy A (index funds)
Is that true? Are there many billionaires who became billionaires through having most of their money in index funds?
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
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