MSc in Computer Science--how do I get into Trading?

Generally, from what I've seen in a technology driven (ie "quant" or "high frequency") firm, the trading support people are staff that facilitate and monitor trading software. Some of the work is admittedly manual rather than mental (ie keying or booking, back office reconciliation, etc). The software will be already established by the trader(s)/directors themselves. You will have little input (especially to start) over programming or implementation.

Often once someone is recruited into that type of position, they will get pigeonholed as a tech person and it will be hard to transition within THAT firm (note I am only speaking from my limited knowledge and experience of smaller proprietary trading).

What I had in mind was say you got hired to trade support based on your technical and programming skill set, then it would be feasible after a year for you to have amassed trading specific knowledge. I would imagine you could then find work as a trading assistant in a group that does algorithmic/quant/strategy trading. Your role would be junior level and involve editing and modifying code, monitoring that the software is functioning properly, What's cool about those role junior trader roles is that typically (but not always!) there's an up or out mentality where you get growing responsibility and eventually would be responsible for trading your own product/strategy. I am only speaking about the path for trading at a proprietary trading firm. I couldn't comment on the path for trading at a hedge fund or bank. I imagine those would be more traditional recruiting from masters programs at elite schools. Online education training comes to mind for a mid-level career switcher and I would ask a program director at such a program if they could offer insight into recruiting specifics for someone of your profile. University of Washington offers an online certificate in computation finance which may be useful for someone like yourself who already has a masters but wants to get exposure to the trading industry.

One thing to consider is the trade off of this path versus staying in your current field, you may find starting at the back on the line to be too expensive especially for the first few years. In Chicago these junior/mid level trading positions typically pay between 40-70 plus 2-8 bonus. My understanding is that is somewhat below programmer/developer salaries. What if you have a hard time making the transition to trading and find yourself stuck in support for 4+ years? Just something to consider.

To get a sense of the overlap between CS and trading, try searching for key words on LinkedIn or Indeed.com and see what jobs are listed. Also maybe informational interview people in positions you would want to have down the road and ask them to explain how they got their start.