Performance of Underlying Assets: NMPAX's price is heavily influenced by the performance of the assets it holds. Positive performance leads to price increases, while poor performance results in price decreases.

Interest Rate Changes: Rising interest rates can negatively impact bond prices within NMPAX, especially if the fund holds long-term bonds. Conversely, falling rates can boost bond prices.

Credit Risk: Changes in the creditworthiness of issuers of bonds held in the portfolio can affect the fund's price. Downgrades can lead to price declines, while upgrades can lead to increases.

Market Sentiment: General market sentiment towards fixed income investments can impact demand for NMPAX shares. Bullish sentiment can increase demand and price, while bearish sentiment can decrease them.

Inflation Expectations: Rising inflation expectations can erode the value of fixed income investments, potentially leading to a decrease in NMPAX's price. Lower inflation expectations can have the opposite effect.

Fund Flows: Large inflows of money into NMPAX can drive up the price, while significant outflows can put downward pressure on it.

Management Fees and Expenses: The expense ratio of NMPAX can indirectly affect its price. Higher expenses can reduce the overall return and potentially impact investor demand.