Interest Rates: As a zero-coupon Treasury ETF, ZROZ's price is highly sensitive to interest rate changes. Rising rates decrease its value, while falling rates increase it.

Inflation Expectations: Higher inflation erodes the real value of future payments, pushing down ZROZ's price. Lower inflation has the opposite effect.

Treasury Yield Curve: Changes in the shape of the yield curve, particularly the long end, significantly impact ZROZ. A steeper curve may decrease its value.

Economic Growth: Strong economic growth can lead to expectations of higher interest rates, thus reducing ZROZ's price. Weaker growth might increase it.

Federal Reserve Policy: Actions and statements by the Federal Reserve regarding monetary policy can influence interest rates and, consequently, ZROZ's price.

Supply and Demand: Market demand for long-duration Treasuries influences ZROZ's price. Higher demand drives prices up, while lower demand causes them to fall.

Global Events: Major global economic or political events can impact risk sentiment and lead to shifts in demand for safe-haven assets like US Treasuries, affecting ZROZ.

ETF Flows: Large inflows into ZROZ can drive up its price, while significant outflows can put downward pressure on it.

Time to Maturity: As ZROZ approaches the maturity date of the underlying zero-coupon bonds, its price sensitivity to interest rate changes decreases.