Moody's Investors Service has added to its group that covers residential mortgage-backed securities. The move comes amid some internal moves and is designed help with increasing levels of issuance as interest rates stay low, firm officials say. Phoebe Yu joined earlier this month as an associate analyst focusing on new deals and surveillance for RMBS deals. Yu is a recent graduate of the Massachusetts Institute of Technology's Sloan School of Management, where she did work on prepayment analysis. Also joining is Adrian Chan, previously of United Overseas Bank in Singapore. She started at the end of June. Both new hires report to Pramila Gupta and Jay Siegel, co-heads of RMBS ratings in New York.