Why did U.S. gasoline climb just 3.7% this month while crude gained 19.2%?

U.S. gasoline is 4.295, up 3.7% over the past month. In a month when crude did far more than that, a 3.7% move at the pump is the number worth a closer look, because it does not match what happened underneath it.

The first thing I checked was crude. WTI is 99.27, up 19.2% over thirty days, with a high of 102.48 and a low of 68.25. Brent is 103.96, up 16.8%. So crude rose about five times as fast as gasoline. Over a single month that gap is unusual. Pump prices lag crude, but they usually lag by less than this, and they usually move in the same rough proportion.

The cause of the crude move is not a mystery. The wire has oil at four-month highs on war risk in the Gulf. During the week Brent traded around $107.86 and WTI reached $102.28, both above where WTI sits now at 99.27, and Brent topped $108 earlier in the week. RBC Capital Markets' Helima Croft warned that Brent could top $120 by year end if the fighting continues, citing threats to shipping through the Bab el-Mandeb and Houthi advances near Red Sea ports. So the crude side has a clear driver and a real premium built into it.

If crude ran that hard, the question becomes where the extra barrel value went, because it did not go into gasoline. I checked diesel next. U.S. diesel is 5.967, up 13.5%, and that figure is also its thirty-day high, so diesel is at the top of its range right now, not off a peak. The wire matches it: diesel passed $6 a gallon for the first time, with record highs reported in 28 states. ULSD futures are 4.799, up 11.5%, with a thirty-day high of 5.057. Distillate took most of the move that crude handed the product barrel.

That points to why gasoline lagged. When crude rises on a security scare in the Gulf, the fear attaches to middle distillate first, because that is the fuel that moves freight and gets stockpiled when supply looks shaky. Refiners can shift yield toward diesel when diesel pays better, and the price signal this month told them to. Gasoline got what was left.

The refiner margin points the same way. The 3:2:1 crack spread is 55.72, down 9.57 over thirty days. It fell even with crude up 19.2% and diesel at a record, because gasoline barely moved while the crude input cost jumped and strong diesel could not make up the difference. Refiners had a good diesel month and a tighter overall margin at the same time.

Gasoline's own path inside the month is the part I did not expect. The current price is 4.295, but the thirty-day high is 4.628. So gasoline reached 4.628 at some point and came back down to where it is now. The 3.7% net figure understates what actually happened. Some of the crude spike did pass through to the pump, pushed gasoline to its 4.628 high, and then eased back off. The month-end number is a gasoline price that already gave back part of its own run while crude and diesel held near their highs.

For the operator selling diesel, the month reads well and the numbers say so plainly. The diesel retail-wholesale spread is 1.3 now, up 0.233 over thirty days. Retail diesel margin widened while volume prices set records, so a marketer or retailer with diesel throughput earned more per gallon on more expensive fuel. Anyone weighted toward diesel had a good month and earned it, carrying the inventory risk of a product at an all-time high. The gasoline-heavy retailer had the opposite month: input crude up sharply, street price up only 3.7% and already off its peak, so the margin between what they paid and what they could charge got thinner.

Natural gas storage is 110.47, up 5.2%, near the top of its range, and it does not change the gasoline story. Nothing in these numbers says gasoline demand pulled prices up. Gasoline rose because crude dragged it, and it rose the least of anything on the board because the market wanted distillate more.

So the honest answer is that the 3.7% shows gasoline lagging crude. Crude spiked on Gulf war risk. The added barrel value went into diesel. Gasoline took what was left and then gave some of it back. What I am sure of is that distillate captured this month's move and that refiners' blended margin tightened despite it. What I am not sure of is how long gasoline stays this cheap against crude. If crude holds near 99 and the war premium sticks, gasoline could catch up and the pump could climb further from here. If the premium fades, gasoline may be the first to come off. The crack spread at 55.72 is the number I would watch to tell which way it breaks.

And that was just the data. See you tomorrow.