Underlying Bond Prices: GRNB.US's price is heavily influenced by the prices of the green bonds it holds. Rising bond prices increase the ETF's NAV and market price.

Interest Rate Changes: As interest rates rise, bond prices generally fall, negatively affecting GRNB.US. Conversely, falling rates can boost bond values.

Creditworthiness of Issuers: Downgrades in the credit ratings of green bond issuers held by the ETF can lower its value, while upgrades can increase it.

Supply and Demand: Higher demand for GRNB.US can push its market price above its NAV, and increased supply can cause the opposite effect.

Green Bond Market Sentiment: Positive sentiment towards green bonds and ESG investing can drive increased investment in GRNB.US.

ETF Management Fees: The ETF's expense ratio slightly reduces returns, impacting its price over time.

Inflation Expectations: Rising inflation expectations can lead to higher interest rates, pressuring bond prices and GRNB.US.

Liquidity of Underlying Bonds: Difficulties in trading the ETF's underlying bonds can affect its price and NAV accuracy.