The response should not be conversational. Global Stock Market Performance: ISPDX tracks global ex-US developed market equities; strong or weak performance in those markets directly influences its price.

Currency Fluctuations: Changes in exchange rates between the US dollar and the currencies of the companies within ISPDX's portfolio impact its returns.

Economic Growth in Developed Markets: Economic expansion or contraction in countries like Japan, Germany, and the UK affects the profitability of companies in those regions, thus influencing ISPDX's value.

Interest Rate Policies: Interest rate decisions by central banks in developed economies outside the US can affect corporate borrowing costs and overall market sentiment, influencing ISPDX.

Investor Sentiment: General investor confidence or fear towards international equities can drive buying or selling pressure on ISPDX, impacting its price.

Company Specific News: Major news events affecting the largest holdings within ISPDX can lead to price fluctuations.

Dividend Yields: The dividend yields of the underlying stocks within ISPDX can affect its attractiveness to investors and its overall price.

Expense Ratio: ISPDX's expense ratio, the annual cost to manage the fund, impacts net returns and, consequently, its price.

Supply and Demand: The relative supply and demand for ISPDX shares themselves can influence its price, although this is usually a secondary factor.

Geopolitical Events: Global events such as political instability, trade wars, or unexpected crises can significantly affect market sentiment and the price of ISPDX.