First Trust Vest U.S. Equity Buffer ETF - August seeks to provide the unitholders with returns (before fees, expenses and taxes) that match the price return of the SPDR® S&P 500® ETF Trust (the "Underlying ETF") up to 18.70% cap (before fees, expenses and taxes), while providing a buffer against the first 10% (before fees, expenses and taxes) of a decrease in the market price of the Underlying ETF, over a period of approximately one year from the third Friday of August of each year to on or about the third Friday of August of the following year.