They've lost about 1/5 of their value.

On Thursday, the last trading day of the year, Brent was down around 1% while U S West Texas Intermediate lost just under a percent.

But prices have rebounded strongly of late as governments rolled out stimulus.

Both Brent and W T I have more than doubled from the decade lows seen in April, when prices fell into negative territory for the first time, sending shockwaves across the market.

But a monthly Reuters poll on Thursday showed oil prices are not expected to make much progress in 2021 while rollouts of vaccines and trillions of dollars worth of fiscal support are expected to boost spending, Concerns over lockdowns are expected to cap gains.

New restrictions in Britain have hit near term demand weighing on prices, while hospitalizations and infections have surged in parts of Europe and Africa.

The next major oil price driver will be a January, the fourth meeting of the Organization of the Petroleum Exporting Countries and allies including Russia, a group known as OPEC.