iShares US Mortgage Backed Securities UCITS ETF USD (Dist) (IMBS.L) seeks to track the performance of an index composed of investment-grade mortgage-backed pass-through securities issued by U.S. government agencies, including those from the Federal National Mortgage Association (Fannie Mae, 38-39% weighting), Federal Home Loan Mortgage Corporation (Freddie Mac, 30-31% weighting), and Government National Mortgage Association (Ginnie Mae, 21-22% weighting); uniform mortgage-backed securities; and smaller holdings in legacy pass-throughs such as Federal Home Loan Mortgage Corporation-Gold. The ETF offers investors exposure to USD-denominated, investment-grade agency mortgage-backed securities through physical replication, distributing income semi-annually with a total expense ratio of 0.28%; it maintains high credit quality with moderate interest-rate sensitivity and invests nearly 99% in non-UK bonds alongside minimal cash holdings. Domiciled in Ireland and launched on 23 May 2016, the fund lists on exchanges including the London Stock Exchange (IMBS USD), Deutsche Boerse Xetra (QDVP EUR), and SIX Swiss Exchange, serving investors across Europe, the United Kingdom, Switzerland, Germany, and Mexico with assets under management exceeding EUR 771 million (approximately GBP 2.13 billion fund-wide).