I feel like I need a disclaimer for any of my friends on goodreads that go through and see this book here (all three of you currently). I went through a two day phase of wanting to build an algorithm that day traded stocks and this was part of the "research" phase.
It was actually a decent introduction to the principles of day trading. The best part of the book was about risk and money management, but even that was pretty basic. TL;DR don't risk more than 2% of your account on one trade.
It takes stock trading very seriously, comparing it to running a business. I don't think I'm one to argue, but it all seems rather silly in hindsight. Something like 80 to 90% of day traders lose money: it seems naive to have the confidence to think you can beat them. But then again, this is the era of Robinhood and r/WallStreetBets so who even cares.
As for my algorithm project, it started as a lovely idea. A little Raspberry Pi with a LCD screen that would trade stocks for me. Two days of research and a book later and I find myself wondering why I didn't realize that if this was easy, everyone would be doing it. Suffice to say it isn't easy. The data is hard to gather and clean. The algorithm needs to run on a viable strategy and all of the popular ones aren't exactly profitable, nor applicable to algorithmic trading. There so many inefficiencies that need to be accounted for, including slippage, the spread, liquidity, commissions, and backtesting biases, just to name a few.
I don't want to say I'm giving up on this side project because that feels icky. I've just learned enough to know that I don't know enough to make this yet. Yes, it's frustrating, but it's also something to work towards eventually. For now though, all the money is "safe" away in ETF's.