Speaking as a kdb programmer in finance (although for an unusual use case), most big (and some small) banks have an Enterprise license and have one or more team

Speaking as a kdb programmer in finance (although for an unusual use case), most big (and some small) banks have an Enterprise license and have one or more teams that maintain a market data store and/or an order reporting/reconciliation/PNL stack. There are a decent number of hedge funds that use it for more or less the same purpose but work with other data sets in addition to market data For storing and exposing market data, you need very little additional code. Maintenance is a different story.