Bitcoin has been billed as the “currency of the future.”

Well, bitcoin users call it that, anyway. It’s a cryptocurrency, created with complex computer algorithms as an alternative to dollars, pounds, and other government-sanctioned currencies.

Back in 2010, when the currency was in its infancy, a software developer named Laszlo Hanyecz used it to buy two pizzas. It was the first documented use of bitcoin for a real-world purchase, and it was a landmark moment.

For the two pizzas, the developer spent 10,000 bitcoin. At the time, bitcoin was practically worthless—but that’s no longer the case.

Fueled by a surging Japanese market and global political unrest, the price of bitcoin has soared. Today, the currency hit an all-time high of $2,250 USD, and it seems to hit a new high every few days.

That means that if he’d held onto those 10,000 bitcoin, the developer would have about $20 million today.

At the time, however, it was only about $40.

“”I’ll pay 10,000 bitcoins for a couple of pizzas,” Hanyecz wrote at the time, posting on the Bitcoin Talk forum, “like maybe 2 large ones so I have some left over for the next day.”

“I like having left over [sic] pizza to nibble on later. You can make the pizza yourself and bring it to my house or order it for me from a delivery place, but what I’m aiming for is getting food delivered in exchange for bitcoins where I don’t have to order or prepare it myself, kind of like ordering a ‘breakfast platter’ at a hotel or something, they just bring you something to eat and you’re happy!”

“I like things like onions, peppers, sausage, mushrooms, tomatoes, pepperoni, etc.. just standard stuff no weird fish topping or anything like that. I also like regular cheese pizzas which may be cheaper to prepare or otherwise acquire.”

“If you’re interested please let me know and we can work out a deal.”

Some economists are critical of the merits of bitcoin, as they note that it lacks some of the fundamental features of a traditional currency. Fewer bitcoins are created over time, so there’s a built-in incentive to save bitcoin instead of spending it.

Still, the cryptocurrency continues to gain traction in spite of several sudden price crashes in its history.

Cryptocurrency expert Ben Carmitchel of believes that we’ll continue to see higher prices for all cryptocurrencies, but especially bitcoin.

“Bitcoin price will continue to rise exponentially while its use as a currency transmission tool increases,” Carmitchel said.

Carmitchel notes that the price may fluctuate in the next several weeks, as is common when bitcoin receives significant press coverage. However, he believes that we haven’t seen bitcoin peak due to the fundamental characteristics of how the cryptocurrency is created and used.

“Regardless of a hard fork, the world’s most powerful supercomputer could never be stopped,” Carmitchel said. “I can’t imagine a safer investment.”

In other words, if you’ve got any bitcoin, you’re better off holding onto it—and you certainly wouldn’t want to trade any for a couple of pizzas.