Of course it depends on the situation. If you are saving for retirement, you will be waiting on the money for years regardless.

If you will need the money in the short-term there are other options/indices (e.g. bonds) that are safer given market volatility but will yield lower returns most likely.

If you want to speculate and try timing the market, I'd suggest mentally separating the money into a different category and accept the possibility that you may lose it or end up with terrible returns. I would try not to consider category that as "investment"