The latest round of sell-offs are "all about the tariffs," says Ken Mahoney. He says clarity around future tariffs action will break the "Groundhog Day" cycle of repeated selling action. As the VIX hovers around the high-20s, Ken urges investors to not be afraid of adding ETFs and related investments to portfolios. He picks Nvidia (NVDA), Microsoft (MSFT) and Apple (AAPL) as the leaders in an expected tech-led comeback.