As global trading trends race toward 24-hour, no-days-off markets, the U.S. Commodity Futures Trading Commission argued that it may be fine for the new blockchain-native players, but that expanded hours might not be appropriate for some of the traditional markets, the derivatives watchdog said in a Friday letter issued to the wide waterfront of firms it regulates.

The advisory — coming on the same day that the agency gave a consequential green light to native crypto platforms offering perpetual futures contracts — marks what may be a growing divide between the traditional firms and the new entrants.

“Because of inherent differences between underlying markets, switching to 24/7 trading and clearing may not currently be suitable for all…