Canadian cannabis companies including Canopy Growth Corp., Aphria Inc. and MedReleaf Corp. plunged on a report that U.S. Attorney General Jeff Sessions will rescind policies allowing for the expansion of legal marijuana without federal intervention. ETFMG Alternative Harvest ETF, the first pure-play pot ETF to be listed in the U.S., fell almost 5 percent.

Canopy Growth, the world’s largest medical marijuana producer, fell 10 percent to C$32.21 at 9:38 a.m. in Toronto, while Aphria plunged almost 13 percent to C$18.73, the most since Oct. 17. MedReleaf fell 6.5 percent to C$28.01, its biggest decline since Nov. 14.

The Associated Press reported that Sessions is rescinding the Obama-era policy that allowed legalized marijuana to flourish in states across the U.S., citing two people with knowledge of the situation.

The move, which comes just days after California began selling recreational pot, would leave it to U.S. attorneys where pot is legal to decide whether to aggressively enforce federal marijuana law.