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.

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.

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.