Fundamentally, the price (Net Asset Value, or NAV) of JIIRX.US, a mutual fund, is affected by the underlying assets it holds.

**Market Performance**: The overall performance of the markets in which the fund invests significantly impacts its NAV. Rising markets generally lead to higher NAVs.

**Security Selection**: The specific stocks or bonds held within JIIRX.US directly influence its price. Good stock/bond choices boost returns, while poor ones reduce them.

**Interest Rates**: Changes in interest rates, particularly if JIIRX.US holds bonds, can affect its price. Rising rates typically decrease bond values.

**Fund Expenses**: Management fees and other operational expenses are deducted from the fund's assets, which can slightly lower the daily NAV.

**Investor Demand**: Large inflows or outflows of money from JIIRX.US can indirectly influence its price by forcing the fund manager to buy or sell holdings.

**Economic Indicators**: Macroeconomic factors like inflation, GDP growth, and unemployment can impact the performance of companies and sectors held by the fund.

**Currency Fluctuations**: If JIIRX.US invests in foreign assets, changes in exchange rates can affect its US dollar value.