Fund Performance: WTSYX.US's performance relative to its benchmark and peer funds greatly influences its price. Superior returns attract investors, driving up demand and the price.

Market Conditions: Broad market trends, economic indicators like interest rates and inflation, and investor sentiment affect overall fund flows and, therefore, the price of WTSYX.US.

Interest Rate Environment: Changes in interest rates impact bond yields, which directly affect bond fund prices like WTSYX.US, as well as investor's willingness to hold bonds.

Fund Flows: Net inflows (more money entering the fund than leaving) typically increase the fund's assets and potentially its price, while net outflows can decrease it.

Credit Risk: The creditworthiness of the bonds held by WTSYX.US influences its price. Downgrades in credit ratings can lead to price declines.

Liquidity: The ease with which the underlying bonds in WTSYX.US can be bought and sold impacts the fund's perceived risk and, consequently, its price. Illiquid assets can lower the value.

Management Fees & Expenses: Higher expense ratios can negatively affect the fund's net returns, potentially making it less attractive to investors and impacting its price.