Phillips 66 (PSX) is staring down an estimated $900 million loss tied to the Iran-driven oil price spike, which compresses the crack spread — the gap between crude input costs and refined product prices — that refiners depend on for profitability. PSX already reported a thin 3.4% net margin on $132.4B in FY revenue (down 7.5% YoY), leaving little buffer against a sustained crude price shock; at $10.79 diluted EPS, the stock's earnings power is highly sensitive to crack spread moves.

The key question is whether the Iran situation escalates further or de-escalates quickly, as the refining margin hit is largely transient if crude retreats. Investors will want to watch weekly crack spread data, any PSX guidance updates, and whether competing refiners like VLO or MPC show similar exposure — a sector-wide margin compression versus a PSX-specific issue is a critical distinction.