What Is Bitcoin Mining?
Bitcoin mining is the process by which new bitcoins are entered into circulation; it is also the way that new transactions are confirmed by the network and a critical component of the maintenance and development of the blockchain ledger. "Mining" is performed using sophisticated hardware that solves an extremely complex computational math problem. The first computer to find the solution to the problem is awarded the next block of bitcoins and the process begins again.
Cryptocurrency mining is painstaking, costly, and only sporadically rewarding. Nonetheless, mining has a magnetic appeal for many investors interested in cryptocurrency because of the fact that miners are rewarded for their work with crypto tokens. This may be because entrepreneurial types see mining as pennies from heaven, like California gold prospectors in 1849. And if you are technologically inclined, why not do it?
However, before you invest the time and equipment, read this explainer to see whether mining is really for you. We will focus primarily on Bitcoin (throughout, we'll use "Bitcoin" when referring to the network or the cryptocurrency as a concept, and "bitcoin" when we're referring to a quantity of individual tokens).
Key Takeaways
By mining, you can earn cryptocurrency without having to put down money for it.
Bitcoin miners receive Bitcoin as a reward for completing "blocks" of verified transactions, which are added to the blockchain.
Mining rewards are paid to the miner who discovers a solution to a complex hashing puzzle first, and the probability that a participant will be the one to discover the solution is related to the portion of the total mining power on the network.
You need either a GPU (graphics processing unit) or an application-specific integrated circuit (ASIC) in order to set up a mining rig.
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A New Gold Rush
The primary draw for many mining is the prospect of being rewarded with Bitcoin. That said, you certainly don't have to be a miner to own cryptocurrency tokens. You can also buy cryptocurrencies using fiat currency; you can trade it on an exchange like Bitstamp using another crypto (as an example, using Ethereum or NEO to buy Bitcoin); you even can earn it by shopping, publishing blog posts on platforms that pay users in cryptocurrency, or even set up interest-earning crypto accounts.
An example of a crypto blog platform is Steemit, which is kind of like Medium except that users can reward bloggers by paying them in a proprietary cryptocurrency called STEEM. STEEM can then be traded elsewhere for Bitcoin.
The Bitcoin reward that miners receive is an incentive that motivates people to assist in the primary purpose of mining: to legitimize and monitor Bitcoin transactions, ensuring their validity. Because these responsibilities are spread among many users all over the world, Bitcoin is a "decentralized" cryptocurrency, or one that does not rely on any central authority like a central bank or government to oversee its regulation.
Mining to Prevent Double Spend
Miners are getting paid for their work as auditors. They are doing the work of verifying the legitimacy of Bitcoin transactions. This convention is meant to keep Bitcoin users honest and was conceived by Bitcoin's founder, Satoshi Nakamoto.1 By verifying transactions, miners are helping to prevent the "double-spending problem."
Double spending is a scenario in which a Bitcoin owner illicitly spends the same bitcoin twice. With physical currency, this isn't an issue: once you hand someone a $20 bill to buy a bottle of vodka, you no longer have it, so there's no danger you could use that same $20 bill to buy lotto tickets next door. While there is the possibility of counterfeit cash being made, it is not exactly the same as literally spending the same dollar twice. With digital currency, however, as the Investopedia dictionary explains, "there is a risk that the holder could make a copy of the digital token and send it to a merchant or another party while retaining the original."
Let's say you had one legitimate $20 bill and one counterfeit of that same $20. If you were to try to spend both the real bill and the fake one, someone that took the trouble of looking at both of the bills' serial numbers would see that they were the same number, and thus one of them had to be false. What a Bitcoin miner does is analogous to that—they check transactions to make sure that users have not illegitimately tried to spend the same bitcoin twice. This isn't a perfect analogy—we'll explain in more detail below.
Only 1 megabyte of transaction data can fit into a single bitcoin block. The 1 MB limit was set by Satoshi Nakamoto, and this has become a matter of controversy as some miners believe the block size should be increased to accommodate more data, which would effectively mean that the bitcoin network could process and verify transactions more quickly.
"So after all that work spent mining, I might still not get any bitcoin for it?"
That is correct. To earn bitcoins, you need to be the first miner to arrive at the right answer, or closest answer, to a numeric problem. This process is also known as proof of work (PoW).
"What do you mean, 'the right answer to a numeric problem'?"
The good news: No advanced math or computation is really involved. You may have heard that miners are solving difficult mathematical problems—that's true but not because the math itself is hard. What they're actually doing is trying to be the first miner to come up with a 64-digit hexadecimal number (a "hash") that is less than or equal to the target hash. It's basically guesswork.1
The bad news: It's a matter of guesswork or randomness, but with the total number of possible guesses for each of these problems being on the order of trillions, it's incredibly arduous work. And the number of possible solutions only increases the more miners that join the mining network (known as the mining difficulty). In order to solve a problem first, miners need a lot of computing power. To mine successfully, you need to have a high "hash rate," which is measured in terms gigahashes per second (GH/s) and terahashes per second (TH/s).
If you want to estimate how much bitcoin you could mine with your mining rig's hash rate, the site Cryptocompare offers a helpful calculator. Other web resources offer similar tools.
Mining and Bitcoin Circulation
In addition to lining the pockets of miners and supporting the Bitcoin ecosystem, mining serves another vital purpose: It is the only way to release new cryptocurrency into circulation. In other words, miners are basically "minting" currency. For example, as of September 2021, there were around 18.82 million bitcoins in circulation, out of an ultimate total of 21 million.2
Aside from the coins minted via the genesis block (the very first block, which was created by founder Satoshi Nakamoto), every single one of those bitcoins came into being because of miners. In the absence of miners, Bitcoin as a network would still exist and be usable, but there would never be any additional bitcoin. However, because the rate of bitcoin "mined" is reduced over time, the final bitcoin won't be circulated until around the year 2140. This does not mean that transactions will cease to be verified. Miners will continue to verify transactions and will be paid in fees for doing so in order to keep the integrity of Bitcoin's network.3
Aside from the short-term Bitcoin payoff, being a coin miner can give you "voting" power when changes are proposed in the Bitcoin network protocol. This is known as a BIP (Bitcoin Improvement Protocol). In other words, miners have some degree of influence on the decision-making process on such matters as forking.
How Much a Miner Earns
The rewards for Bitcoin mining are reduced by half roughly every four years.1 When bitcoin was first mined in 2009, mining one block would earn you 50 BTC. In 2012, this was halved to 25 BTC. By 2016, this was halved again to 12.5 BTC. On May 11, 2020, the reward halved again to 6.25 BTC.
In September of 2021, the price of Bitcoin was about $45,000 per bitcoin, which means you'd have earned $281,250 (6.25 x 17,900) for completing a block.4 Not a bad incentive to solve that complex hash problem detailed above, it might seem.
1. Shopping Rewards
Lolli, a Google Chrome or Firefox browser extension, offers “Bitcoin Back” when you shop with its retail partners. It works similarly to browser extensions like Rakuten or Honey that offer discounts and cash back when you use the portal or extension to shop online. Like those programs, Lolli rewards you for spending regular money just as you normally would when shopping online — not for making purchases with crypto.
Retailers on Lolli range from Nike to Sephora to Malaysia Airlines. Rewards go from 1% to as much as 30% Bitcoin back, depending on the retailer and product. Your rewards will go into your Lolli account, and then you can transfer them to your crypto wallet or exchange account.
2. Credit Cards
A cryptocurrency credit card works similarly to other rewards credit cards, but instead of earning cash back or points with every swipe, you’ll get cryptocurrency. While we love simple cash back rewards (and you can always buy crypto with your cash back earnings), these cards can help you more seamlessly pad your crypto portfolio.
Gemini and other exchanges have announced plans for cryptocurrency rewards credit cards, along with fintech companies like BlockFi and Upgrade. The rewards categories on these cards are similar to many traditional cash back credit cards. BlockFi Credit Card, for example, earns a flat 1.5% back in Bitcoin on every purchase you make, after earning 3.5% back for the first 90 days after account opening.
In addition to varying rewards rates, each of these cards offer different redemption values. The Gemini card will let you choose which crypto to redeem rewards in, while BlockFi earns Bitcoin rewards, and others limit your rewards to only certain altcoins.
As with any credit card, the rewards you earn with these cards are only valuable if you avoid their high interest rates. If you use a card to earn crypto rewards, make sure you charge only what you can afford to pay off in full and on time each month, without carrying a debt balance.
3. Look Out for Exchange Sign-Up and Referral Bonuses
Some cryptocurrency exchanges offer sign-up or referral bonuses for using their services. A previous Coinbase sign-up bonus offered $5 to new users to invest in crypto, for example, and the exchange currently offers a $10 bonus to both you and your referral when they make an account and trade at least $100.
Make sure you pay attention to the terms of these bonuses. You may be required to provide more personal information or go through other actions to claim these rewards. Most of these offerings aren’t lucrative enough to warrant signing up for an entirely new exchange if you already have an account, but if you’re a beginner, keep an eye on exchanges you’re considering to see if they offer a sign-up bonus or referral for other friends that may be interested.
4. Coinbase Earn
Popular cryptocurrency exchange Coinbase offers incentives for using the platform’s Learn hub. In order to get the free change, you’ll need to watch Coinbase’s videos, take quizzes, and then Coinbase will deposit a small amount of crypto into your wallet. The content is typically focused on a specific altcoin (like GRT and BOND) and, as a result, these are the coins you’ll earn for going through the lessons.
Because altcoins generally aren’t recommended for long-term investing, you can convert these lesser-known coins into Bitcoin or Ethereum once you earn them. But remember to keep track of these transactions, as every crypto-to-crypto trade is taxable. Additionally, you should track the price value of all your earnings through Coinbase Earn, and report them as income on your federal tax return. If you earn over $600 through the program, Coinbase will issue you a Form 1099-MISC, which you can use to report your earnings.
You’ll need to have a funded Coinbase account, live in an eligible country, and verify all of your personal information to start earning with Coinbase Earn.
5. Earn Interest on Your Bitcoin
A few crypto exchanges allow you to earn interest on your cryptocurrency holdings. Gemini Earn, for example, is a lending program in which you lend your crypto to institutional borrowers and can earn up to 7.4% APY. BlockFi has a similar offering, BlockFi Interest Account, which accrues interest up to 7.5%. Lending your crypto out to these institutions can add even more risk on top of the built-in risk of cryptocurrency, so make sure you read the terms carefully before you sign up and don’t lend more than you can afford to lose.
You can also earn interest by staking on some crypto exchanges, like Binance.US. Staking means leaving cryptocurrency in your wallet to earn rewards or interest. By doing so you help maintain the blockchain network. You can usually only stake certain coins within an exchange, which may require buying into more risky altcoins to reap the benefits.
Interest you earn on your crypto as well as earnings from staking are both taxable, and your responsibility to report as income. If you choose to participate, you’ll need to track the cost basis of your earnings throughout the year to include on your tax return.
6. Airdrops
Of all the methods for earning free crypto, airdrops carry the most risk — more than we believe is worth the benefit for most investors. Developers perform airdrops when they want to gain traction for their new cryptocurrency. Put simply, they give away coins to try and garner adoption.
You can look online to find when airdrop projects are happening; they’re often promoted on the company’s website as well as by users on social media platforms and some crypto news sites. If you qualify, the developers often send the specified amount of coins straight to your digital wallet address.
It’s important to be cautious with any new cryptocurrency projects. Fake airdrops and ICOs— initial coin offerings — are common scams used by hackers. Even when they are real, many of the coins issued in airdrops are not a great investment store of value. Experts recommend sticking with the most well-known cryptos, Bitcoin and Ethereum, especially for beginners. If you follow that recommendation, then pass on airdrops.
Any crypto you earn through airdrops is also taxable income. You’ll be responsible for reporting it as such based on its fair market value on the date it was recorded on the distributed ledger (in most cases, when you receive the airdrop into your digital wallet), according to the IRS.
[READ MORE]: Cryptocurrency Crime Is Booming. Here’s How to Invest Safely
Bottom Line
Even though there are ways to earn extra crypto for free, don’t let the temptation of freebies force your hand. Cryptocurrency is a very volatile, new investment, and you should only ever put in what you’re OK with losing.
Free crypto also might not be free come tax season. Any crypto that may be considered income, as well as crypto-to-crypto conversions or holdings you cash out for U.S. dollars, is taxable. You’ll need to track the market price of any crypto you get when you receive it, and again when you sell it, to report to the IRS come tax season.
[READ MORE]: Yes, Your Crypto Is Taxable. Here’s How to Report Virtual Currency to the IRS
