Money is a common language we all agree to use to convey the value of things. Since the Chinese starting using cowrie shells as an early form of currency more than 3,000 years ago, societies everywhere have been looking for forms of money that are portable, divisible, durable, and reasonably stable in supply. Over time, money has become less physical and more symbolic: tangible commodities such as gold have given way to tokenized paper and now to ephemeral digits in a computer.

The proliferation of digital communication technologies means we can now marshal our money with remarkable speed and ease—checking balances from a mobile phone, making a payment pretty much anywhere merely by showing a thin slab of plastic, buying and selling stock over the Internet. Yet beyond the transactional speed and convenience, our concept of money and the ways we handle it have not been radically transformed.