The problem with things like _A Random Walk..._ is that they're geared towards helping independent investors; that's great, but it's not super relevant to a tech career in finance. On the other hand, knowing how shopping a block works: pretty handy.
http://www.classiccmp.org/transputer/finengineer/
But there's probably also lots of information available on your intranet - there's bound to be a wiki with some good information. And if your company subscribes to the ISDA library (about £11k pa) you can get a userid & dig out stuff there. What I found most useful was to get a copy of trade confirms & read them until I understood - plus copy some modelling spreadsheets & tinker with the inputs to see what effect they have on the outputs. For really heavy financial maths subscribe (for free) to Willmott & search around there. Good luck.
Edit: Sorry-- I forgot to say this is a book! It's by Burton Malkiel. (It's not particularly US-centric.)
The thing is - Charlie Munger, Warren Buffett, Philip Carret, and a few others DON'T operate like normal financial firms and have done spectacularly better. To understand financial firms you need to know what works better - and Berkshire Hathaway works a whole lot better. And Charlie Munger is Warren Buffett's sounding board.
Read Charlie Munger's advice and compare it to what you read elsewhere about financial firms knowing that Charlie is right.
In fact, the OP reasons in much the way of Buffett (I read several of his eariler articles), except that his noodling around with shorts is a departure from what I take to be Buffett's strategy of buying good management and good companies at good prices, and waiting as long as it takes to get good prices.