Is the Explosion of Single-Stock ETFs an Opportunity or a Danger?

The Magnificent 7 account for roughly a third of the entire S&P 500, so it's understandable that some investors might consider focusing an outsized portion of their portfolio on either one of these stocks or a similarly-sized titan of the market. At the same time, single-stock exchange-traded funds (ETFs)—funds that take the common diversification tactic of ETFs and flip it in order to provide leveraged exposure to a single name—have proliferated quickly.