Well the OP says the retail rate went from 5.5% to 6% as a consequence. Not very significant either, right?

Surprise comes from data that violates your expectations. I guess it’s mostly a matter of expectations here.

Also, ETF buyers are probably less knowledgeable / professional / sophisticated than buyers of the underlying asset.

The ETF has a redemption mechanism that keeps its trading price aligned with the underlying net asset value. Thus, the sophistication of the ETF buyers is irrelevant.

Good point.