Crude oil futures tumbled at the open Sunday after OPEC decided to boost output. WTI crde (CL1:COM) -3.8% and Brent (CO1:COM) -3.5% dropped more than 3%. Eight members of OPEC+ on Saturday announced a second straight monthly increase of 411K barrels of crude per day for June.

The group agreed to raise output in June, a sign that Saudi Arabia and its allies appear to be weary of cutting output and may be trying to appease President Trump, who has pushed for lower prices.

Oil prices fell more than $1 a barrel on Monday as OPEC+ is set to further speed up oil output hikes, spurring concerns about more supply coming into a market clouded by an uncertain demand outlook.