And that’s not only because a chamomile sour costs $17 (or 0.16 bitcoins). It’s because whenever someone new uses bitcoins, the electronic currency’s value tends to increase. Shrem has bought thousands of bitcoins for about $20 each, starting in 2011. Since then, the digital coins have soared in value to $109.

 

That’s turned the 23-year-old into a millionaire and into one of a handful of early bitcoin investors who’ve decided to sink their windfalls back into the bitcoin economy, starting their own companies and investing in others.