Interest Rates: Rising interest rates typically cause bond prices, including NTBAX.US, to fall, as newly issued bonds become more attractive.

Credit Risk: Changes in the perceived creditworthiness of the bond issuers within NTBAX.US’s portfolio can impact its price; increased risk leads to lower prices.

Inflation Expectations: Higher inflation expectations usually drive bond yields up and prices down, affecting NTBAX.US negatively.

Economic Growth: Stronger economic growth might reduce demand for bonds as investors favor riskier assets, potentially lowering NTBAX.US's price.

Market Sentiment: Overall investor sentiment and risk appetite can influence bond prices; negative sentiment can lead to price declines.

Duration: NTBAX.US’s duration, a measure of its sensitivity to interest rate changes, affects how much its price will fluctuate with rate movements.

Liquidity: Changes in the fund's liquidity can impact its price, with less liquid funds potentially experiencing wider price swings.

Fund Flows: Large inflows into NTBAX.US can drive up its price, while large outflows can lead to price declines.