Underlying Assets: YMAR.US aims to track the performance of a specific index. Changes in the value of the underlying assets (typically mortgage-backed securities) within that index directly impact the ETF's price.

Interest Rates: Rising interest rates generally decrease the value of existing mortgage-backed securities, potentially lowering YMAR.US's price. Conversely, falling rates can increase its value.

Market Sentiment: Investor confidence or fear regarding the housing market and mortgage-backed securities influences demand for YMAR.US. Positive sentiment tends to drive up the price, while negative sentiment can lead to price declines.

Supply and Demand: Like any ETF, the balance between buyers and sellers of YMAR.US shares affects its price. Higher demand relative to supply results in a higher price, and vice versa.

Expense Ratio: Although not a direct price driver, the ETF's expense ratio (fees charged to manage the fund) affects its overall return and attractiveness to investors, indirectly impacting its price over time.