Computers are the new Dumb Money

> 2) If your algorithm does not take the value of the holdings of an ETF into account you deserve to lose money.

Even if there is a large discrepancy between the value of an ETF and the value of the holdings, it might still make sense to sell if you expect the value of the holdings to plummet further, and the mismatch to go away by the value of the original holdings tanking, rather than the ETF rebounding.

Maybe an intelligent trader could try and arbitrage this somehow (maybe buy/hold ETF, and short underlying assets), but your trading platform would have to have some form of extra option besides buy/sell a given ETF.