What is bitcoin?
You heard about this bitcoin thing?
Every bitcoin story must include an image of a physical bitcoin. Note: Physical bitcoin coins do not really exist.
We're guessing: yes, you have. The first and most famous digital cryptocurrency has been racking up headlines this year due to a breathtaking rise in value -- cracking the $1,000 threshold for the first time on Jan. 1 before ascending to nearly $19,000 this month.
Bitcoin involves technology, currency, math, economics and social dynamics. It's multifaceted, highly technical and still very much evolving. This explainer is meant to clarify some of the fundamental concepts and provide answers to some basic bitcoin questions.
But first: A quick backstory
Bitcoin was invented in 2009 by a person (or group) who called himself Satoshi Nakamoto. His stated goal was to create "a new electronic cash system" that was "completely decentralized with no server or central authority." After cultivating the concept and technology, in 2011, Nakamoto turned over the source code and domains to others in the bitcoin community, and subsequently vanished. (Check out the New Yorker's great profile of Nakamoto from 2011.)
What is bitcoin?
Simply put, bitcoin is a digital currency. No bills to print or coins to mint. It's decentralized -- there's no government, institution (like a bank) or other authority that controls it. Owners are anonymous; instead of using names, tax IDs, or social security numbers, bitcoin connects buyers and sellers through encryption keys. And it isn't issued from the top down like traditional currency; rather, bitcoin is "mined" by powerful computers connected to the internet.
How does one 'mine' bitcoin?
A person (or group, or company) mines bitcoin by doing a combination of advanced math and record-keeping. Here's how it works. When someone sends a bitcoin to someone else, the network records that transaction, and all of the others made over a certain period of time, in a "block." Computers running special software -- the "miners" -- inscribe these transactions in a gigantic digital ledger. These blocks are known, collectively, as the "blockchain" -- an eternal, openly accessible record of all the transactions that have ever been made.
Using specialized software and increasingly powerful (and energy-intensive) hardware, miners convert these blocks into sequences of code, known as a "hash." This is somewhat more dramatic than it sounds; producing a hash requires serious computational power, and thousands of miners compete simultaneously to do it. It's like thousands of chefs feverishly racing to prepare a new, extremely complicated dish -- and only the first one to serve up a perfect version of it ends up getting paid.
When a new hash is generated, it's placed at the end of the blockchain, which is then publicly updated and propagated. For his or her trouble, the miner currently gets 12.5 bitcoins -- which, in December 2017, is worth more than $225,000. Note that the amount of awarded bitcoins decreases over time.
What determines the value of a bitcoin?
Ultimately, the value of a bitcoin is determined by what people will pay for it. In this way, there's a similarity to how stocks are priced.
The protocol established by Satoshi Nakamoto dictates that only 21 million bitcoins can ever be mined -- about 12 million have been mined so far -- so there is a limited supply, like with gold and other precious metals, but no real intrinsic value. (There are numerous mathematical and economic theories about why Nakamoto chose the number 21 million.) This makes bitcoin different from stocks, which usually have some relationship to a company's actual or potential earnings.