Yes, they do. I did not dispute that. But as I said (perhaps not sufficiently clearly--my mistake), and as other posters have pointed out, this neutralizes out

Yes, they do. I did not dispute that. But as I said (perhaps not sufficiently clearly--my mistake), and as other posters have pointed out, this neutralizes out over the 30-year time horizon of an index fund investment. One dollar invested in the S&P 500 in 1970 would become $43.12 in 2000, for example, despite the crashes of 73, 87, and 2000. I repeat, if the market were bad enough that these crashes actually wiped out your account over a 30 year period, nobody would make money in the market at all. Index funds are a low-risk, low-return investment with low management fees. They're a much better investment choice for a retirement account than algorithmically trading that money. And if you were good enough at algo trading to make solid returns over time, you might as well quit your day job and open a hedge fund or asset management shop.