From the Trading Floor blog:
Hedge Funds and other large money managers cut their net-long exposure to Brent crude oil by 36,515 contracts of futures and options during the week of January 7. This was the biggest weekly reduction since May 2012 and it occurred in response to the continued weakness seen since December 27. Gas oil net-longs were cut by 38 percent.
As the table below shows, the significant reduction in Brent crude longs was driven by cuts in gross longs and the addition of gross short positions.
Source: Ice Exchange, Bloomberg and Saxo Bank
Source: Ice Exchange, Bloomberg and Saxo Bank