> No, because to do that you have to have deliberately kept money out of investments, waiting for a downturn.

Not wrong about always being fully invested, but an argument for perhaps have some portion (10-20%) being in bonds to (a) reduce volatility which may help with preventing panic when things inevitably (temporarily) downturn, and (b) having some 'dry powder' available for rebalancing (sell high, buy low).

The returns of the S&P 500 was 0% between 2000 and 2010, but if you had ~20% bonds you actually got positive returns:

* https://www.forbes.com/sites/investor/2010/12/17/the-lost-de...

See also Japan in 1980s: having some component in (even domestic JP) bonds allowed you to rebalance out of a rising market over time.

Waiting for the dip is generally sub-optimal for returns:

* https://ofdollarsanddata.com/even-god-couldnt-beat-dollar-co...

It may depend on the investment profile of the individual. I’m not 100% invested which means there’s always some cash available at any point.

> I’m not 100% invested which means there’s always some cash available at any point.

This is sub-optimal from a returns perspective:

* https://ofdollarsanddata.com/even-god-couldnt-beat-dollar-co...

Yes as I say, it means having funds deliberately not invested waiting for a crash, which is timing the market and relies on you predicting the market.