Just wondering if there are any non-obvious risks of buying some long put options in one of the US index ETFs.

Obviously there is exchange rate risk since it'll be USD denominated. And the serious risk that my little punt doesn't pay off before option expiry (would be 1 year expiry).

So if for example i was to buy USD$3000 of put options with a strike that is say 10% below the current ETF value.

If the bull market keeps going I lose the $3k when the options expire worthless.

If the sector tanks as I expect it will sooner or later, then I make (Strike - option price - ETF value) at sale.

Is there counterparty risk I need to be aware of? or any other risks.
My first time looking at put options, have only purchased call options before, and still waiting for those to pay off.