Market Interest Rates: Rising interest rates generally decrease bond prices, leading to a lower net asset value for JSJFX. Lower interest rates typically increase bond prices, resulting in a higher NAV.

Credit Quality of Holdings: Downgrades in the credit ratings of bonds held by JSJFX can decrease their market value, lowering the fund's NAV. Conversely, upgrades can increase the NAV.

Economic Growth: Strong economic growth can lead to higher inflation expectations, potentially causing interest rates to rise and bond prices to fall, impacting JSJFX negatively. Slow economic growth might have the opposite effect.

Inflation Expectations: Rising inflation erodes the purchasing power of future bond payments, leading to lower bond prices and a lower JSJFX NAV. Stable or declining inflation can be beneficial.

Supply and Demand for Bonds: Increased demand for bonds generally pushes prices higher, increasing the NAV. Greater supply can decrease prices, lowering the NAV.

Fund Management Expertise: Skillful management of the fund's portfolio, including strategic asset allocation and security selection, can enhance returns and positively impact the NAV. Poor management can lead to negative performance.

Fund Expenses: Higher expense ratios can detract from the fund's overall returns, resulting in a lower NAV compared to similar funds with lower expenses.

Investor Sentiment: General market optimism or pessimism can influence bond prices, indirectly affecting the NAV of JSJFX.