A deal between Saudi Arabia and Russia to freeze oil output failed to stem the biggest drop in bullish bets since July.
The agreement reached on February 16 isn't going to revive crude prices, according to Goldman Sachs. Iran said it supported the deal, without saying whether it would temper its own production. A ban on Iran's oil exports was lifted last month when the Persian Gulf country completed the conditions of a nuclear deal with world powers.
"This agreement is not going to do anything in terms of reducing the surplus," said Bart Melek, head of commodity strategy at TD Securities in Toronto. "Iran will probably produce as much oil as it can to regain some market share."
Speculators' long positions in West Texas Intermediate futures and options fell by 5.3 percent during the week ended February 16, according to U.S. Commodity Futures Trading Commission data, the biggest decline in seven months. West Texas Intermediate crude futures rose 3.9 percent to $29.04 a barrel in the period covered by the report, and traded at $31.65 at 11:10 a.m. Monday.
The Saudi Arabia-Russia deal to fix production at January levels, which also includes Qatar and Venezuela, is the "beginning of a process" that could require "other steps to stabilise and improve the market," Saudi Oil Minister Ali al-Naimi said in Doha after the talks.