What happen if ETF closes?

Your broker should notify you, nothing gets lost. the ETF's value is transferred into your account as cash.

problem: you possibly wanted to invest longterm and when you reinvest this new cash you'll incur new fees.

The ETFs that get closed mostly are the smaller ones (AUM, assets under management), because the longterm small ones do not produce much fee income for the issuing company.

Many believe that ETFs that are prone to closure are those with AUM less than 100-200 mio USD equivalent. So better select the bigger ones.🍀​​​