Fidelity announced zero expense ratio Index Funds

Seems too good to be true. I wonder if there's a catch 🤔

I was wondering what the “catch” may be too. The money to pay management fees and record keeping fees has to come from somewhere. But I guess at the scale Fidelity operates, that money can be provided by other means. Maybe analogous to credit cards giving rewards being paid by people who can’t manage credit cards... they collect a fee from all the high fee funds that they hope to refer people to later ;) I also understand that some amount of equities lending exists for these funds so they can make some money on the side. Maybe those won’t be passed on to the fund holders in this case. I plan to look into it more but I’m already in funds with fees from 0.01%-0.07% so it may be negligible. They also are following their own index so it’s unclear how that may deviate from a more established index. They could decide not to include certain equities because of a more expensive cost to invest. That being said, I like fidelity and hope this works out for them and keeps competition up for the market.