etf - SERP Analysis

https://en.wikipedia.org/wiki/Exchange-traded_fund

https://www.etf.com/

https://www.investor.gov/introduction-investing/investing-basics/glossary/exchange-traded-fund-etf

https://etfdb.com/

https://investor.vanguard.com/investment-products/etfs

https://www.finra.org/investors/investing/investment-products/exchange-traded-funds-and-products

https://www.fidelity.com/etfs/investing-in-etfs

https://www.merrilledge.com/investor-education/understanding-etfs

https://etf.wi.gov/