It takes at least two people to conspire. It isn't unusual for businesses to conspire. It is secretly or privately planning how to get ahead or win, often by doing something wrong. It's the theory part that can be mistaken. It is trying to figure out how (or if) the other guys are conspiring (so your team can beat them, for example). The word conspiracy has most often been applied to plots to overthrow a government, so it carries that connotation.