Concerted action can take as many forms as human imagination and ingenuity permit and does not require a formal agreement. And parallel action, coupled with other evidence of collusion (e.g., secret meetings or other suspicious conduct) can be the basis of an antitrust violation.

That said, normally, the mere fact of parallel action is not problematic unless there is more to show suspicious activities. The venture financing industry has many customs and patterns of long-standing, and its participants will happen to conform to them for a variety of reasons having nothing to do with collusion aimed at suppressing competition.