This is not advice, but if I were 100% or even 50% in cash and had at least 20 years left of time horizon, with no immediate need for the cash, I'd probably put

This is not advice, but if I were 100% or even 50% in cash and had at least 20 years left of time horizon, with no immediate need for the cash, I'd probably put 5% back in the market each month until I had 100% allocation. But... the US does feel heated up, so who knows?