You mean the missile part or the loss estimates?

Ukraine claimed it was a 'locally made weapon' and they don't have anything else with this much power based on the explosions.

At least that's what the experts I follow on Twitter are claiming. Lots of people claiming ATACMS which I doubt.

It can be also Grim ballistic missile, actually. More or less equivalent of Iskander.

Was ATACMS sold to Ukraine?

Official line is No