Oil prices are headed for their largest weekly rise in over a year on Friday, spurred by escalating Middle East tensions that have cast a pall over global markets ahead of the weekend. Most equity indexes and stock futures were in the black, but gains were capped as investors speculated that Israel could imminently carry out retaliatory strikes on Iran. Brent crude futures were set to gain around 8% for the week - its steepest since February 2023, while U.S. crude futures' 8.2% weekly rise would be the largest since March last year.