The iBoxx GBP Non-Gilts Fallen Angels Index is designed to measure the performance of high yield, GBP-denominated fallen angel bonds that were previously rated investment grade and were part of the Markit iBoxx GBP Benchmark Index. The index includes sovereign, sub-sovereign and corporate bonds, with a minimum amount outstanding of GBP 250 million for bonds issued after Dec. 31, 2010, while bonds issued before this date require GBP 250 million for insertions and GBP 100 million for existing bonds. Bonds must have a remaining time to maturity of at least one year at rebalancing and a rating of B or BB.