Are there any commonly known triggers for computerized trading algorithms

that can be anticipated based on specific market activity?

Yes, but all strategies are different. If it’s a high-frequency trading algo, it has entered and exited a trade before you can blink. All other trading automation depends on each strategy, there are thousands of strategies, maybe even tens of thousands.

I personally run a handful of automated strategies in MetaTrader 5 on stocks and it’s not in my best interest to share how they work exactly. :)