Bob Diamond, former Barclays PLC (LSE:BARC) chief and part of traditional finance’s old guard, has given his take on the recent insurgence into the cryptocurrency sector by some of the world’s largest financial institutions. Asked on CNBC’s Squawk Box if he was surprised to see the likes of BlackRock Inc (NYSE:BLK), Citadel and Charles Schwab (NYSE:SCHW) muzzling in on the underregulated and over-scrutinised decentralised economy, Diamond was as straightforward as it comes.