In the last 16 years (since the financial crash) the US economy has roughly doubled in size. Even with the recent drop, the S&P500 is at over 5x the 2009 level. The rise in the last 16 years is crazy large and I can easily see a lot more of it unwinding.

That mantra "just buy the S&P" has been chanted over and over. WEB has recommended that. The Bogleheads swear by it. Irritating individuals on the old board preached it. It has been told so often for so long that it can't possible be wrong. Or can it? OK, it was oversold in 2009, but those numbers are scary, as are the other metrics. The safe and standard strategy is looking like it has developed a self-fulfilled bubble. It was amazing the outrage and horror at the rather modest dip that Trump initiated, when the 1 year result was still acceptable and the two year return pretty good. The general investing population seems to be unrealistic in their expectations and a likely reversion to long term means is going to make some serious waves. I don't see a big upside to buying the dips, and at my age, I feel some security in selling the upticks.