Section 1 of the Sherman Act, 15 U.S.C. § 1, prohibits “every contract, combination … or conspiracy, in restraint of trade or commerce.” Determining whether such a “contract, combination … or conspiracy” (i.e., the agreement element of a Section 1 claim) actually exists is a fact-intensive inquiry.

Parties frequently assume that evidence that the alleged conspirators engaged in parallel conduct (e.g., they adopted the same pricing or economic terms) is sufficient to satisfy the agreement element of a Section 1 violation. However, the Supreme Court of the United States has stated that “[a] statement of parallel conduct, even conduct consciously undertaken, needs some setting suggesting the agreement necessary to make out a § 1 claim; without that further circumstance pointing toward a meeting of the minds, an account of a defendant’s commercial efforts stays in neutral territory.”

The necessary “setting suggesting the agreement” (referred to as “plus factors”) can come in many forms. Some courts have stated that plus factors may fall into one of the following categories: (1) evidence of motive to enter into the agreement, (2) evidence that the defendants acted contrary to their own interests, or (3) evidence implying a traditional conspiracy. Importantly, absent a “plus factor,” parallel conduct generally will not give rise to a viable antitrust claim.