New Delhi, Oct. 15 -- One unwritten law of finance is that any stock we buy loses momentum almost immediately, whereas any stock we sell, invariably surges afterwards. And as anyone who has spent even a little time in the market can attest, the second hurts way more than the first. But anytime you are feeling miserable about your selling decisions or missed chances, remember this name-Laszlo Hanyecz.

On 22 May 2010, this Florida-based programmer received two large pizzas from a Papa John's outlet. And etched his name into history books.

Why? Because Hanyecz used 10,000 Bitcoins for the meal, making it the first documented real-world transaction using cryptocurrency.

But more mind-bending are its financial dimensions. The 10,000 Bitcoin...