Phillips 66 (PSX) stock intrinsic value fair value estimate & owner earnings analysis

Phillips 66 is an integrated downstream energy company. It owns refineries, a pipeline and natural gas liquids (NGL) business (Midstream), a 50% stake in a chemicals joint venture, marketing and specialty products, and a renewable fuels business. Refining earnings swing hard with margins; Midstream and Marketing provide steadier cash. How we measure earnings. We start from operating cash flow, strip out the swings in receivables, inventories and payables, deduct stock compensation as a real cost, and deduct all capital spending. Because refinery revenue moves mostly with oil prices rather than with added capacity, we treated all capital spending as upkeep, which is conservative. On that basis, owner earnings per share over the last ten years were: 2016 -$1.02, 2017 $3.11, 2018 $10.77, 2019 $3.52, 2020 -$1.39, 2021 $4.30, 2022 $17.61, 2023 $14.10, 2024 $6.49, 2025 $9.04. This is a genuine full cycle with two loss years and two boom years, so we anchor on the ten-year median of about $5.40 per share rather than the strong 2022-2023 results or the weaker 2024. Growth check. Owner earnings rose about 39% in 2025 (from $6.49 to $9.04). We assume no growth in the first year of the base case, starting at or below the anchor, because the 2025 rebound reflects refining margins we cannot name a durable cause for. Share buybacks have cut the diluted share count from about 530 million in 2016 to about 408 million in 2025, but the company slowed repurchases to $1.2 billion in 2025 while it works to reduce debt, so we give no credit for further buyback-driven per-share growth. What changed in the business. In the fourth quarter of 2025 the Los Angeles Refinery stopped producing fuel and is being idled, removing that capacity. In April 2025 the company acquired the Coastal Bend NGL pipelines and fractionators (about $2.2 billion), and on October 1, 2025 it began consolidating the WRB refining joint venture. Management now plans total annual capital spending of about $2.5 billion including WRB, in line with the roughly $2.5 billion annual average of the last ten years, which supports using the historical capital burden. Refineries ran at 94% of capacity in 2025. Base case, about $55 per share. Owner earnings stay at about $5.40 a year for ten years, then fade in a straight line to zero over the following fifteen years. The fade is there because we can point to no evidence of earning power beyond that horizon: the refining assets are long-lived and well run, but nothing in the filings secures demand for refined fuels that far out. Bear case, about $14 per share. The business earns about $1.50 a year, close to the 2016-2017 and 2019-2020 experience of thin or negative margins, for ten years and then fades to zero over ten years. Debt is a real burden in this case: total debt was $19.7 billion at year-end 2025 against equity of $30.2 billion, and management targets $17 billion by the end of 2027. Interest is already deducted in our earnings figure, so we did not subtract debt again. Bull case, about $103 per share. Owner earnings run near $10 a year, which is roughly the 2023-2025 average, for ten years, then fade to zero over fifteen. This assumes the consolidated WRB refineries and the Coastal Bend assets already acquired keep operating at the recent high utilization. We do not assume margin expansion, new projects or a market recovery. What would make us wrong. A prolonged refining downturn like 2020 lasting several years, or a rapid fall in fuel demand within the next decade, would push results toward or below the bear case. Owner earnings for the last two years were dragged down or lifted by working-capital swings that we have removed, and the latest quarterly filing has not been used to change the level. Margin-of-safety price, $33 per share. This is roughly 40% below the base value, a wide margin because refining earnings are cyclical, two of the last ten years were losses, and the company carries substantial debt.