CNBC’s Courtney Reagan spoke with Tom Lydon, Vice Chairman of VettaFi, and Christian Magoon, CEO of Amplify ETFs. They broke down the latest ETF flows, talked standout summer trends and tackled what’s ahead for the markets in September. Will there be a September swoon ahead? They also did a deep dive on thematic ETFs like bitcoin and marijuana, as recent regulatory developments are making big waves in the ETF business on both fronts.