[elemeno]

My rule of thumb these days is that the smaller and more obscure the hedge fund, the more likely it is that they're using an unusual set of languages. The more PhDs they have, the more likely they're using something weird like K!

[crntaylor]

I used K (well, actually the combination of Q and kdb+) in my previous job at an investment bank, and I've used it (to a lesser degree) in my current job at a hedge fund (disclaimer: I have a PhD...).

K/Q is a beautiful language - it's uncompromisingly terse, extremely powerful, and very fast. The interop with kbd+ (a lightning fast, column-oriented, in-memory database) is gorgeous.

It has an unfortunate reputation for obscurity, stemming mainly from the people who think it's fun to write your entire program as a K one-liner and remove all the whitespace. You can write perfectly clear code in Q - super modular, concise, and well documented. It's just that a lot of Q programmers don't bother.