It's the closing party of ETHDenver, a weeklong cryptocurrency conference dedicated to the blockchain Ethereum. Lines have stretched around the block for days. Now, on this Sunday night in February, the giddy energy is peaking.

But as the crowd pushes inside, a wiry man with elfin features is sprinting out of the venue, past astonished selfie takers and venture capitalists. Some call out, imploring him to stay; others even chase him down the street, on foot and on scooters. Yet the man outruns them all, disappearing into the privacy of his hotel lobby, alone.Vitalik Buterin, the most influential person in crypto, didn't come to Denver to party. He doesn't drink or particularly enjoy crowds. Not that there isn't plenty for the 28-year-old creator of Ethereum to celebrate. Nine years ago, Buterin dreamed up Ethereum as a way to leverage the blockchain technology underlying Bitcoin for all sorts of uses beyond currency.