Goldman is very unlikely to have decided proactively to cut off traders access, and it's much more likely there was an operational loss. What kind of loss? I don't know but consider:

1) Claude Code is only being taken away from traders.

2) Only traders have permission to send orders to the market and book client trades.

3) Claude code would probably have been running as the trader, under their account with minimal review.

If you run a coding agent in that environment it's only a matter of time until it enters a bad order or books a bad trade, and once that happens it's only a matter of time before management decides to take this kind of action.

Goldman is definitely not doing this for cost reasons. They can afford the tokens.