Fund managers sold another 32 million barrels of Brent futures and options in the week to Dec. 4, bringing total sales over the last 10 weeks to a record 360 million barrels.
Funds now hold just over two long positions for every short one, down from a ratio of more than 19:1 at the end of September, and the least-bullish position for 17 months.
Bearish short positions have risen to 117 million barrels, up from just 27 million at the end of September, and the largest number since June 2017.
Pessimism about the outlook for crude prices was reflected by a similar collapse in sentiment towards middle distillates such as gasoil.
Fund managers sold another 20 million barrels of European gasoil, bringing total sales in the last eight weeks to 82 million barrels.
Funds are the least-bullish towards middle distillates since July 2017, according to an analysis of position data from ICE Futures Europe.
Middle distillates are heavily geared towards the economic cycle because most distillate fuel oil is used in freight transportation (shipping, railroads, aviation, trucks), manufacturing, mining and farming.
So the collapse in sentiment towards distillates is consistent with growing concerns about the outlook for the global economy in 2019.
Investors' fears about the impact of trade tensions and heightened uncertainty on business investment and growth next year is darkening the outlook for distillates just as it is hitting equity markets.
Expected oversupply of crude has been reflected in the sharp fall in Brent spot prices since the start of October and the futures curve swinging from backwardation into contango.
OPEC and selected non-OPEC countries agreed last week to cut their output by 1.2 million barrels per day during the first six months of 2019 from the level in October 2018.
Most of the cuts will come from Saudi Arabia, with smaller contributions likely to come from Russia, the United Arab Emirates, Kuwait and Oman.
Other OPEC and non-OPEC countries are unlikely to reduce their output voluntarily by any significant amount so their participation in the agreement is mostly symbolic.
The planned production cuts reverse the OPEC+ group's earlier ramp up in output and should offset the softer enforcement of U.S. sanctions on Iran.
By cutting output promptly and aggressively, OPEC+ may be able to avert a large build up in excess oil inventories next year and a collapse in prices similar to 2014/15.
In contrast to 2014, Saudi-led OPEC has opted to sacrifice market share in an effort to defend prices at a higher level despite the rapid growth of U.S. shale.
But there is little the group can do about the deteriorating economic outlook, which implies the need for a period of lower oil prices to restrain production and stimulate consumption to keep the market balanced.
And as the global economy reels from the tariff war between the United States and China, rising interest rates, tightening credit conditions, and a broader economic slowdown, lower oil prices are a necessary part of the economic adjustment process.
(Editing by David Evans) ((email@example.com; and on twitter @JKempEnergy))