The U.S. Securities and Exchange Commission has stepped in to stop the launch of some of the most aggressive exchange-traded funds ever proposed in the country. The products were designed to deliver three to five times the daily performance of stocks and cryptocurrencies, pushing the limits of how much risk regulators are willing to allow. ETF Issuers Pull Filings After SEC Flags Leverage Rule Violations On Tuesday, the agency issued nine warning letters to major ETF providers, including Direxion, ProSh ...