MFS Charter Income Trust is a closed-ended mutual fund focusing on fixed income investments globally. Managed by Massachusetts Financial Services Company, it primarily invests in a diverse range of corporate bonds, U.S. and foreign government securities, as well as mortgage-backed and asset-backed securities. The fund aims for a balanced portfolio through fundamental and quantitative analysis, targeting both U.S. and emerging market issuers. It measures its success against several key bond indexes, offering investors a strategic approach to income investing since its inception in 1989.