Marathon Petroleum (MPC) concentration risks

The company's only disclosed concentration in the 10-K is a supply-side dependency at the foundation of its operating model: the company does not produce any of its crude oil feedstocks — a high share by disclosed size with a dependency character. For a refining business, crude oil is the primary input, meaning the company is entirely exposed to third-party supply availability, pricing, and logistics for its key raw material. Unlike an integrated producer that controls upstream output, this company must source all feedstocks through external markets, bilateral contracts, or pipeline arrangements, creating an inherent vulnerability to supply disruptions, crude differentials, and counterparty reliability at the input level. The character of this exposure is dependency rather than structural in the strict sense: it reflects a deliberate strategic choice to operate as a pure-play refiner rather than integrate upstream, but it means the company has no proprietary control over the single largest cost input in its business. Crude availability, quality specifications, and transportation logistics are therefore external variables that management can hedge or contract around but cannot eliminate. There is no disclosed customer, geographic, or additional supplier concentration layered on top of this input dependency in the available source claims. On balance, the disclosed profile is narrow: a single high-share supply-side exposure that is well understood as a structural feature of the pure-play refining business model and that manifests primarily through crude cost and margin volatility.

For the engine’s reasoning on MPC’s current verdict — including which dimensions drove the score — see the per-dimension breakdown.

Concentration counts reflect items disclosed in each peer’s most recent 10-K; disclosed-size classification uses TrendMatrix’s internal 10-K extraction taxonomy.