High IV doesn’t make the trade good

If your first thought is “IV rank is high, this is attractive,” you’re missing the point.

IV rank tells you relative pricing vs history. It does not tell you what is happening right now.  Often the high IV rank names have the more negative carry (VRP) which is not the best time to sell options.  Just look at metals right now.

When realized volatility triples, the question isn’t whether premium looks rich. The question is whether your capital can tolerate a 2–3x expansion in the daily trading range without forcing you to adjust at the worst moment.

If one-day realized moves have expanded from 0.8% to 2.5%, your position size must contract accordingly to maintain the same PNL volatility— even if the setup looks “better.”

If you don’t reduce size when realized expands, you're letting the volatility of the asset control the volatility of your PNL, just when things have become more uncertain. 

Also, the chances are all the option dealers are also short vol, which is why it's trading rich in the first place, and that doesn't tend to foster near-term stability.

Before you enter the trade, answer this:

If realized volatility doubles from here, does my size still allow me to hold structure without adjustment?

If the answer is no, the trade isn’t wrong. But your size definitely is.