By now, you’ve probably heard of Bitcoin. But, no one really knows the man behind the digital currency. He or she is a computer programmer named Satoshi Nakamoto.

The identity of this person is thought to be a pseudonym representing a man, a woman, or even a group of people… but its a mystery.

Since bitcoin was created in 2008, no one’s been able to figure out who Nakamoto is. They published a nine-page white paper that year that included the first-ever mention of Bitcoin, calling it a “peer-to-peer electronic cash system.” That same year, Nakamoto released bitcoin’s first software online, partnering with developers and coders to improve it… which went on until 2011 when, without warning, Nakamoto vanished.

According to CNBC, Nakamoto told a fellow bitcoin developer that they had “moved on to other things.” However, its estimated that Nakamoto walked away with a stash of around a million Bitcoins before disappearing. Today, that would equal around $5 billion.

Nakamoto’s one million bitcoins amount to five percent of the entire cryptocurrency. To put it into perspective, Bitcoin has a finite supply of 21 million, which is expected to be reached by the year 2140.

With that much of a horde of the digital currency, Nakamoto has the power to tank Bitcoin if he wants, reports CNBC. Bitcoin is valuable because its rare, so if Nakamoto chose to sale and flood the market with so many bitcoin at once, it could have a huge effect on its value.

On the flip side, if Nakamoto holds onto his stash of Bitcoin and it becomes a global currency, he could become the richest person in the world.

With all that said, it makes sense that Nakamoto remain anoymous. They have privacy, protection and peace. For the owner of such a fortune and the power to tank an entire currency, that’s a good thing for them.