Regarding Fed announcements, I update my systems once a year with "blocked trade days" that tell the systems not to trade on those days. This takes about 10 minutes. I see this instruction as part of the systems. btw, those who say system trading doesn't work should revise their words to say that THEIR systems don't work. The evidence that some systems do work is available to anyone who does a little research.
a shitload of people lose money trading with automated systems but i would bet even more lose money that leave the decisions up to their own crazed by fear and greed discretion. for sure, there are lots of people making tons of money through discretionary trading but the most successful folks i know are using some form of automation, be it with a complicated set of unknown (to me)parameters with the data punched in just prior to the open or even big pairtraders with 200+ pairs on at all times. even a simple, automated program for doing OPG(open only) orders where you merely enter the variance % relative to yesterday's close, the price now and the futures to fair market value and you can enter orders for 1000 different stocks that if filled will get out of all of them within a few minutes. imagine getting filled on even 100 stocks and having to try to manually get out of them right quick. you ever have a seizure? some people actually make money doing it. me about even at it over a couple of years so it isn't my focus but a good way to get into the game for the day. just look at the truly big boys with their algorithmic arbitrage systems, the ones that keep the Spoo and cash market as tight as protons and neutrons. those are all fully automated and you think they are not making any money?