I had a thread a years back where I answered questions about the industry. My experiences have matured a little since then and there's still a lot I don't know, but I'm fortunate to have lived through these years with a few new battle scars and war stories to tell.
About myself: I run the electronic market making business at a trading firm, and we trade cash equities, futures, OOF and cash FX. We grew from zero to 9 digits within our first 36 months. I've architected our trading engine end-to-end from scratch, everything from our own feed handling to order execution, to the post-trade and data management stack. This had to be redone completely a couple of times owing to costly mistakes. There's more lines of code in our infrastructure than on all of SpaceX's vehicles combined. Our trading strategies are latency sensitive, and we are usually 1st or 2nd in the queue on the products we make markets in, but it took about a year to get it working despite an experienced team, a very clear set of plans and thorough design specs. It was extremely difficult and we got quite lucky.
I'm particularly interested to help people who're in college or grad school and thinking of their career choices, or to talk about social issues around electronic market making. I'll answer within my means although I won't speak in detail about issues that surround our competitive advantage. I'll take questions posted here from now up to Wednesday, although my replies may take till next Sunday due to time constraints.