I don't know about that. If a general financial crisis is the concern, stocks outside the S&P 500 would not be spared. What I got from this interview was just

I don't know about that. If a general financial crisis is the concern, stocks outside the S&P 500 would not be spared. What I got from this interview was just a reminder that it makes sense not to get caught up in enthusiasm for a certain asset. And investors (including me) are certainly enthusiastic about the S&P 500 index fund.