or you could sell a single broad market etf lol. or buy a short etf.. it hasn't been hard to selectively exposure yourself to dang near any slice of equities since the ETF boom

Short ETFs are usually leveraged and make for a really good way to lose money.

Realistically, timing is the issue. "This is a bubble" is worth ~nothing. "This is a bubble and it will pop in late December" is worth a lot if you're correct.

the question was of exposure, not timing.