More suitable word for 'reactionary' [closed]

I'm looking for a word to describe a group of people who reacts whenever something happens. They are sure to react and are so nearsighted that their reactions are predictable. I was going to use the word 'reactionary' but realized that term has a specific political meaning. Is there a better word I can use for this purpose?

Example: A conversation where "the industry is completely stupidly reactionary" comes up when they are talking about the stock market and how it reacts predictably to the news.

I think you're looking for something like "Pavlovian response" or "knee-jerk reaction".

The bigger problem is that your use of "react" and "stupidly" is 100% subjective. Many people react to reaction-worthy things: something falls from the roof, a gust of wind etc. The mere fact that people react to something doesn't mean anything. If your claim is that their reaction is wrong, you need to justify your claim.