Refiner Stocks Just Had Their Worst Day Since the Tariff Shock
Valero just posted the most profitable quarter in its history, yet its stock suffered a brutal single-session collapse that wiped out nearly $29 billion across three major refiners. The reason why tells you everything about where refining margins may be…
Valero Energy (NYSE:VLO | VLO Price Prediction) closed at $387.34 on October 27, 2026, down 9.24% from $426.76. The drop came five days after the company reported the most profitable quarter in its history.
Marathon Petroleum (NYSE:MPC) fell 7.36% to $435.98, and Phillips 66 (NYSE:PSX) fell 7.03% to $268.53. By our calculation, the three lost roughly $29 billion of market value in one session.
Fuel futures fell faster than crude, and the president promised cheaper gasoline. The selloff likely reflects investors starting to price in a margin unwind.
Valero Fell Hardest While the Refiner ETF Held Up
Valero traded between $423.26 and $385.65 and closed near the low. It slid another 0.32% after hours.
The VanEck Oil Refiners ETF (NYSEARCA:CRAK) fell only 3.73% to $62.18. In its June 30, 2026 holdings, Marathon, Valero and Phillips 66 made up about 8.03%, 7.31% and 6.25% of the fund. Most of the rest was foreign refiners, which a U.S. margin scare impacts far less.
For Valero, it was the worst session since April 3, 2025, the day after the tariff announcement, when the stock fell 14.47% from $133.62 to $114.29. Marathon’s last worst day was April 10, 2025, a 7.53% drop from $131.42 to $121.53. CRAK’s came on April 4, 2025, a 6.42% slide.
Phillips 66’s last worse day came later, on May 21, 2025, weeks after the tariff shock, when it fell 7.54% from $120.90 to $111.78.
In April 2025, investors feared for demand. The three refiners lost more than $20 billion on concerns that tariffs would slow fuel use.
Fuel Fell Faster Than Crude
This time the threat was to margins, because a refiner earns the gap between fuel prices and crude costs, so that gap shrinks when fuel falls faster than crude.
Heating oil futures, the diesel benchmark, fell 2.79% to $4.7752 a gallon, and RBOB gasoline fell 2.51% to $3.1376. WTI crude lost 1.83% and Brent 1.67%.
At 1:04 PM ET, President Trump posted on Truth Social ahead of a rally in Corpus Christi, Texas. A tanker carrying about 1 million barrels of Venezuelan crude was arriving there, and he predicted more shipments and that “Gasoline and Diesel Prices will soon come plummeting down.”
Luisa Palacios of Columbia University, a former Citgo chair, put the volume at roughly 6% of U.S. refiners’ daily crude input: “Against the U.S. refining system, it’s negligible.” Energy Secretary Chris Wright said more Russian diesel volume could “quite possibly” proceed under the U.S. sanctions waiver. But Valero opened at $420.34, already below its prior close before the post, so no single headline explains the day.
Record Profits Meet a Peak-Margin Fear
On October 22, Valero reported record net income of $6.8 billion and adjusted EPS of $23.90, beating the $20.30 consensus. Its refining margin reached $39.24 a barrel, up from $13.14.
CEO Lane Riggs said, “Our refineries operated at near-record utilization rates, providing a reliable supply of critical transportation fuels.” The selloff prices in a margin peak at a business that is still running well.
Regular gasoline averaged $4.2661 against $3.0520 a year earlier, and diesel at $6.3521 sits just below its $6.5276 record. With midterms ahead, Washington will keep pushing supply measures, and each one is a headline risk.
Valero’s Record Run Faces a Fourth-Quarter Margin Test
Valero is still up 141.52% for the year, more than double its $159.90 low and about 16% below its $461.52 high. The selloff took back only part of a huge run, and that run rests on record-high margins under political pressure.
The risks to Valero’s share price likely skew down. Management calls current margins “very sustainable,” but the share price already assumes that, and a refiner earning record margins has the most to lose when fuel falls faster than crude.
Investors exploring refining exposure may want to compare CRAK, whose global mix of refiners held up far better in this U.S. margin scare.
Phillips 66 reports on October 28 and Marathon on November 3. If both show fourth-quarter margins holding and Valero closes back above $423.26, this downside view is likely wrong.
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Omor Ibne Ehsan is a writer at 24/7 Wall St. He is a self-taught investor with a focus on growth, cyclical, and dividend equities that have strong fundamentals, value, and long-term potential. He also has an interest in high-risk, high-reward investments such as penny stocks.
