More than $18 billion worth of cryptocurrency has moved into a new type of platform which offers investors rewards in exchange for locking up their tokens, in a complex scheme that analysts warn poses a risk for users and the crypto market. Bitcoin, the biggest cryptocurrency, is near all-time highs while ether, the second biggest, is up more than 60% this year. At the heart of the re-staking boom is Seattle-based start-up EigenLayer.