An entire investment sub-industry has sprung up around covered call ETFs. They have boomed in popularity in recent years, with assets under management growing from about $18 billion in early 2022 to roughly $80 billion as of July, according to Morningstar data. Inflows into these ETFs have been driven by the prospect of stock-like price gains combined with bond-style income and low volatility. JPMorgan’s popular Equity Premium Income ETF (JEPI), the largest actively managed ETF in the U.S., says the fund’s aim is to provide “a significant portion of the returns associated with the S&P 500 inde…