Sure, but Jane Street, as mentioned here, is probably the largest user of it that I'm aware of. It is a great language, but F# is the more pragmatic choice these days. OCaml doesn't have a huge ecosystem where as F# inherits all the .NET libraries.
There is also a steep learning and onboarding curve to climb when you onboard new employees. Significantly low help when you face issues, and just overall lack of help and information when you are stuck in a non-trivial issue. This is not just with F# or OCaml, but with all non-C based languages.
Only reason hedge funds can continue using this is they can pay people to suffer through this.