Renewable Identification Number markets dropped sharply in the Aug. 20-Aug. 27 window, according to the EcoEngineers' Carbon Market Snapshot.
In the current year, D4 2026, biomass-based diesel RIN prices traded at $1.95 per RIN on Thursday, down from $2.30/RIN a week ago.
D5 2026 advanced biofuel RINs were trading around $1.94/RIN, below $2.33/RIN last week.
D6 2026 corn-based ethanol RIN prices finished trading on Thursday at $1.83/RIN, down from $2.27/RIN a week ago.
Matt Gammans, assistant professor of agricultural policy at North Dakota State University, toldthat the price drop reflects a change in expectations.
He said the market now thinks the Environmental Protection Agency may grant substantially more 2025 small refinery exemptions than previously expected.
Gammans said that two things shifted that expectation this week. First, the EPA's decision to push back the Sep. 1 compliance deadline for 2025 obligations removed the forced buying that would otherwise have happened in the last week of August and was read as a signal of broader relief.
Second, reporting citing non-public briefings indicated that exemptions could reach 1.8 billion RINs, compared with a market assumption closer to 1.3 billion.
He explained that an exemption erases a refiner's obligation, so the RINs that would have been retired remain on the market.
"This means more RINs available for obligated refiners, which lowers prices. Because obligated refineries are affected by all components of the mandate (D4, D5, D6), an exemption reduces demand for all categories," Gammans said.