Commodity Prices: MLPDX invests in master limited partnerships (MLPs) operating in the energy sector. Fluctuations in oil and gas prices directly impact MLP profitability and thus, the fund's value.

Interest Rates: As MLPs are often income-generating investments, MLPDX's price is sensitive to interest rate changes. Rising rates can make bonds more attractive, decreasing demand for MLPs.

Economic Growth: Economic expansion typically increases energy demand, benefiting MLPs and potentially raising MLPDX's price. Conversely, slower growth can have a negative impact.

Regulatory Changes: Changes in regulations related to the energy industry, such as environmental policies, can significantly affect MLP operations and therefore the fund's performance.

MLP Specific Performance: The performance of individual MLPs within the fund's portfolio directly influences MLPDX's overall value. Company-specific issues affect individual MLP's price.

Market Sentiment: General investor sentiment towards energy investments and MLPs can cause price swings in MLPDX, even independent of fundamental factors.