TMSF invests its assets in fixed income securities, aiming for high income and some capital appreciation. It actively shifts allocations among multiple sectors including, US and foreign high yield and investment-grade corporate debt, mortgage-backed and asset-backed securities, government bonds, and emerging market debt. The fund may invest across all maturities, adjust allocations as opportunities arise, and hedge most foreign currency exposure. It uses a variety of derivatives for purposes including hedging, managing interest rate or credit risk, and gaining market or currency exposure. Asset allocation and portfolio duration are actively managed in response to changing interest rates, credit conditions, and market opportunities, with the flexibility to invest in other T. Rowe Price mutual funds or ETFs.