NEW: CFTC Chairman Mike Selig says the agency is proposing rules that would create a federal regulatory pathway for crypto exchanges to offer retail customers leveraged and margined spot trading, without requiring congressional action. "Unlike the Clarity Act, these regulations wouldn’t require crypto assets to trade on CFTC-registered platforms," Selig wrote in the WSJ. "We don’t have the authority to impose such a requirement without congressional action. But the rules would establish a purpose-fit option for crypto-asset exchanges that wish to operate under a single federal regulatory scheme."