U.S. renewable fuel credits soared on Tuesday to the highest on record, as higher costs for soybean oil pushed up both renewable fuel and biomass-based credits, traders said.

Renewable fuel (D6) credits for 2021 traded at $1.50 each, up from $1.44 in the previous session, traders said. Biomass-based (D4) credits traded at $1.58 each, up from $1.52 previously.

Both were the highest since Reuters began reporting data for renewable fuel credits in 2013 and biomass-based credits in 2014.

Front-month soybean oil, which can be used as a feedstock in biomass-based fuels such as biodiesel, traded at 67.71 cents per pound on Tuesday, the highest since 2008, Refinitiv Eikon data showed.

The credits, known as RINs, rose at the same time that the U.S. Supreme Court on Tuesday was hearing oral arguments for a case involving the U.S. Renewable Fuel Standard, which requires refiners to blend biofuels into their fuel mix each year or buy RINs from those that do.

The Supreme Court’s decision around the case will likely heavily influence the future of the RFS.