Bitcoin is the world’s first decentralized cryptocurrency – a type of digital asset that uses public-key cryptography to record, sign and send transactions over the Bitcoin blockchain – all done without the oversight of a central authority.
The Bitcoin network (with an upper-case “B”) was launched in January 2009 by an anonymous computer programmer or group of programmers under the pseudonym “Satoshi Nakamoto.” The network is a peer-to-peer electronic payment system that uses a cryptocurrency called bitcoin (lower case “b”) to transfer value over the internet or act as a store of value like gold and silver.
Each bitcoin is made up of 100 million satoshis (the smallest units of bitcoin), making individual bitcoin divisible up to eight decimal places. That means anyone can purchase a fraction of a bitcoin with as little as one U.S. dollar.
Bitcoin’s price is renowned for being highly volatile, but despite that, it has become the top performing asset of any class (including stocks, commodities and bonds) over the past decade – climbing a staggering 9,000,000% between 2010 and 2020.
When the cryptocurrency was launched at the beginning of 2009, as Satoshi Nakamoto mined the bitcoin genesis block (the first-ever block on the Bitcoin blockchain), 50 BTC entered circulation at a price of $0.00.
Fifty bitcoin continued to enter circulation every block (created once every 10 minutes) until the first halving event took place in November 2012 (see below). Halvings refer to bitcoin’s issuance system, which was programmed into Bitcoin’s code by Satoshi Nakamoto. It essentially involves automatically halving the number of new BTC entering circulation every 210,000 blocks.
In February 2011, BTC’s price reached parity with the U.S dollar for the first time. The milestone encouraged new investors into the market, and over the next four months, bitcoin’s price continued to rise – peaking at over $30.
By early 2013, the leading cryptocurrency had recovered from a prolonged bearish episode and rose above $1,000, albeit only briefly. But with the infamous Mt Gox hack, China announcing its first ban on crypto and other situations, it took a further four years for the BTC price to return to above $1,000 again. Once that level was passed, however, bitcoin’s price continued to surge dramatically throughout 2017 until BTC peaked at its previous long-standing all-time high of $19,850.
Over 2018, the entire crypto market plunged into what is now known as the “crypto winter” – a yearlong bear market. It wasn’t until December 2020, when bitcoin returned to test the previous all-time high, that it eventually surpassed that historical level and rose a further 239% over the next 119 days to a new all-time high of $64,799.
How does Bitcoin work?
Bitcoin and other cryptocurrencies are like the email of the financial world. The currency doesn’t exist in a physical form, and the coin is transacted directly between the sender and the receiver without banking intermediaries to facilitate the transaction. Everything is done publicly through a transparent, immutable, distributed ledger technology called blockchain.
Here are the main features of blockchain technology:
• Bitcoin transactions are recorded on a public, distributed ledger known as a “blockchain” that anyone can download and help maintain.
• Transactions are sent directly from the sender to the receiver without any intermediaries.
• Holders who store their own bitcoin have complete control over it. It cannot be accessed without the holder’s cryptographic key.
• Bitcoin doesn’t exist in a physical form.
• Bitcoin has a fixed supply of 21 million. No more bitcoin can be created and units of bitcoin cannot be destroyed.
Bitcoin users send and receive coins over the network by inputting the public-key information attached to each person’s digital wallet.
In order to incentivize the distributed network of people verifying bitcoin transactions (miners), a fee is attached to each transaction. The fee is awarded to whichever miner adds the transaction to a new block. Fees work on a first-price auction system, where the higher the fee attached to the transaction, the more likely a miner will process that transaction first.
Every single bitcoin transaction that takes place has to be permanently committed to the Bitcoin blockchain ledger through a process called “mining.” Bitcoin mining refers to the process where miners compete using specialized computer equipment known as application-specific integrated circuit (ASIC) chips to unlock the next block in the chain.
Unlocking blocks work as follows:
• Crypto mining uses a system called cryptographic hashing. This function simply takes any input (messages, words or data of any kind) and turns it into a fixed-length alphanumeric code known as a “hash.”
• Each input creates a completely unique hash, and it’s almost impossible to predict what inputs will create certain hashes. Even changing one character of the input will result in a totally different fixed-length code.
• Each new block has a value called a “target hash.” In order to win the right to fill the next block, miners need to produce a hash that is lower than or equal to the numeric value of the ‘target’ hash. Since hashes are completely random, it’s just a matter of trial and error until one miner is successful.
This method of requiring miners to use machines and spend time and energy trying to achieve something is known as a proof-of-work system and is designed to deter malicious agents from spamming or disrupting the network.
Whoever successfully unlocks the next block is rewarded with a set number of bitcoin known as “block rewards” and gets to add a number of transactions to the new block. They also earn any transaction fees attached to the transactions they add to the new block. A new block is discovered roughly once every 10 minutes.
Bitcoin block rewards decrease over time. Every 210,000 blocks, or about once every four years, the number of bitcoin received from each block reward is halved to gradually reduce the number of bitcoin entering the space over time. As of 2021, miners receive 6.25 bitcoins each time they mine a new block. The next bitcoin halving is expected to occur in 2024 and will see bitcoin block rewards drop to 3.125 bitcoins per block. As the supply of new bitcoin entering the market gets smaller, it will make buying bitcoin more competitive – assuming demand for bitcoin remains high.
Bitcoin’s energy consumption
The process of requiring network contributors to dedicate time and resources to creating new blocks ensures the network remains secure. But that security comes at a price. As of 2021, the Bitcoin network consumes about 93 terawatt hours (TWh) of electricity per year – around the same energy consumed by the 34th-largest country in the world.
This appetite for electricity has drawn widespread criticism from celebrities such as Tesla CEO Elon Musk to government bodies such as China’s State Council and the U.S. Senate over Bitcoin’s impact on climate change. But while the electricity figures are alarmingly high, it’s important to note that bitcoin mining at most accounts for 1.29% of any single country’s energy consumption. Not to mention, Bitcoin is a complete financial system whose energy consumption can be measured and tracked, unlike the fiat system, which cannot be accurately measured and requires a range of additional layers to function, including ATMs, card machines, bank branches, security vehicles, storage facilities and huge data centers.
There are also a number of initiatives including the Crypto Climate Accord and the Bitcoin Mining Council that aim to improve Bitcoin’s carbon footprint by encouraging miners to use renewable sources of energy.
As already mentioned, the Bitcoin network was created by a pseudonymous programmer, or group of programmers, known only as “Satoshi Nakamoto.” During its early development, other developers joined to work on the protocol, including cypherpunk Hal Finney, cryptographers Wei Dai and Nick Szabo and software developer Gavin Andresen.
There were also a range of other developers including Pieter Wuille and Peter Todd who contributed to the development of Bitcoin Core – the first client on the Bitcoin network. A client is a piece of software that enables a network participant to run a node and connect to the blockchain.
An American nonprofit called the Bitcoin Foundation was founded in 2012 to support the development and adoption of the Bitcoin protocol. After three years, however, the foundation eventually ran out of cash and was dissolved.
In 2014, Adam Back, another cypherpunk and the inventor of Hashcash – a cryptographic hashing algorithm created in 1997 which used the same proof-of-work mechanism that Bitcoin would later adopt – co-founded Blockstream. Blockstream is a for-profit tech company that develops new infrastructure on the Bitcoin network, including Lightning Network and sidechains.