At the bank I used to work at, traders had a habit of wandering over and asking questions about the differences between the prices of securities over time (as a

At the bank I used to work at, traders had a habit of wandering over and asking questions about the differences between the prices of securities over time (as arbitrageurs, it's all they thought about). I got so sick of writing one-off SQL queries that I wrote a very small (not much bigger than a calculator) language to express their questions. They liked it, but it had no potential for use outside of our trading desk (which was disbanded a few years later).