PVI is a passively managed ETF that tracks an index that invests in variable rate demand obligations (VRDOs) issued by US municipalities that are exempt from federal taxes. Securities should be denominated in USD and have at least one day remaining term to final maturity. Although VRDOs are typically issued with long-dated maturities, such notes can pay short-term interest to investors. The fund selects investment-grade VRDOs with interest rates that reset daily, weekly, or monthly. The funds holdings are weighted by market value and rebalanced monthly. Prior to March 24, 2021, the fund was called Invesco VRDO Tax-Free Weekly ETF that tracked the Bloomberg U.S. Municipal AMT-Free Weekly VRDO Index. Prior to August 28, 2023, the ETF's name was Invesco VRDO Tax-Free ETF.