Game Theory and Bitcoin: the Miners’ Perspective

Competition drives markets. In traditional financial markets, however, competition is limited to the production of goods and the buying and selling process. With Bitcoin, competition plays a far-deeper role. The minting of new bitcoin, as well as the processing and verification of transactions, are all made more efficient, accurate, and secure, thanks to competition. It’s no surprise, then, that game theory plays a pivotal role in the inner workings of the Bitcoin ecosystem.

A brief explanation of game theory

Game theory models the strategic interaction between players in a scenario with set rules and outcomes where the players are rational and looking to maximize their payoffs. In effect, it’s a more detailed, nuanced way of looking at how incentives affect how things get done.

For example, if your job is to shovel 100 pounds of stone into a hole and you’re all alone and have all the time you want, there’s no game theory involved. On the other hand, if someone else is given the same task and you’re each working with the same pile of stones, the dynamics of the situation change.

They change further if only the person who shovels the most gets paid. And, naturally, if you get paid according to how much you shovel, the outcome of your actions would change in yet another way. Each of these situations will be impacted by game theory and its many models.

Although Bitcoin seeks to espouse concepts like “fairness,” “transparency,” and others that are often incongruent with competition, game theory still plays a primary role in the Bitcoin universe.

How does game theory apply to Bitcoin mining?

Bitcoin mining involves solving math problems that are used to create new bitcoin and verify transactions. To continue with the stone shoveling example, if you have as long as you want to move the pile of stones, you may choose to take your time. Your shovel may move slower than if someone else were involved in the task because then the speed at which you shovel would determine whether you get paid more, less, or at all.

The fact that multiple miners compete to verify transactions and generate coins gives Bitcoin an inherent efficiency: The job gets done faster. To dig a little deeper, three types of game theory driving this process include zero-sum theory, congestion theory, and the Nash equilibrium. Let’s take a closer look at how these concepts work.

Bitcoin mining and zero-sum theory

Zero-sum theory dictates that the “winner” gets the spoils and everyone else walks away with nothing. In the mining of bitcoin, the first person to solve a problem gets the value associated with completing the task. Everyone else gets nothing. If you could take a snapshot of the nanosecond a particular hash is found, you would see one user getting rewarded for their work and the others getting nothing.

However, because the Bitcoin system requires so many problems to be solved all the time, in reality, many miners can earn a relatively steady income. The strategies they use are governed by two other game theory concepts — the congestion theory and the Nash equilibrium.

Bitcoin mining and congestion theory

Congestion theory stipulates that the amount each player gets depends on the resources they choose and how many other players choose the same resources.

For example, imagine there are two stations with trains heading to the same destination, and each train can hold only 10 people. One train station is five miles closer to the destination. If there are 100 people, and everyone goes to the closer station, one train will have to go back and forth 10 times. On the other hand, if some of the passengers go to the closest station and others go to the station farther away, there will be less congestion, and everyone will arrive at the destination sooner.

In Bitcoin mining, many of the decisions of the miners depend on congestion theory. If there was only one miner, all the spoils would go to her or him. On the other hand, Bitcoin is open to all, so each miner has to decide whether they will get in the game — and add to the congestion — knowing that more people are bound to get in the game, decreasing their chance of winning.

Once a miner decides to get involved, they then have other decisions to make regarding the equipment they choose. Faster equipment provides an advantage, similar to getting on the closer train. However, the quicker the equipment, the more electricity it takes to run, which increases the cost of mining.

If a miner’s earnings won’t sufficiently offset the cost of electricity, they may choose not to get involved. They may also choose to forego setting up a mining system and join a mining pool instead, where the electricity costs are absorbed by multiple participants. Congestion theory dictates which “train” each miner takes, as well as when and how they get involved.

In addition, the way the decisions of each miner affects the others is governed largely by another game theory concept: the Nash Equilibrium.

Bitcoin mining and the Nash Equilibrium

In the Nash equilibrium, named after mathematician John Nash from the movie A Beautiful Mind, each “player” recognizes that while they have similar goals, not everyone can get exactly what they want. Therefore, some will choose to settle for a less-desirable outcome, satisfied with the fact that they are at least getting something. All players agree to proceed, happy to share the spoils.

For example, continuing with the stone shoveling scenario, you may be stronger and faster than the other shoveler. Both of you agree to shovel for the same amount of time, but you get 70% of the money while the other shoveler only gets 30%. The other person could protest, but realizing that something is better than nothing, they agree to the terms. At this point, an equilibrium is established. At the end of the day, you both earn money and walk away satisfied.

The worldwide community of miners also follows Nash equilibrium principles. Some miners have more money than others and can afford to purchase the latest mining computers, capable of solving specific hashes faster than older models. Other miners may not have as much money, but they live in areas where electricity is less expensive. They can, therefore, spend less than wealthier miners who live in areas where electricity is more costly. Some live in places where it will never be profitable to mine, so they join a mining pool instead.

Each miner recognizes that their limitations dictate how much they will get. At the same time, all agree to participate, satisfied with their portion at the end of the day — even if it’s just a small fraction of a bitcoin.

How miners are incentivized

Zero-sum theory, congestion theory, and the Nash equilibrium only work because of the ways miners are incentivized and dissuaded from cheating the system. Before mining rewards are approved, the technical infrastructure enforces the “trustless” nature of the Bitcoin network. If miners do not adhere to protocol rules, their block submission will be rejected by other nodes in the blockchain. All network nodes including other miners verify the ledger entries packaged into a new block. If entries are considered invalid, or the block hash doesn’t meet network requirements, the miner’s result will be rejected and the 6.25 BTC will be awarded to another miner.

While the block rewards are enticing at current BTC valuations, there are other financial implications that compel miners to either continue or suspend network operations. No miner will win the worldwide competition each time a new block is added (~every 10 minutes), so they must weigh the probability of profitable successes. There are other factors to consider, too. For example, some miners may decide to bow out when electricity becomes too expensive. Others however, may have a longer time horizon and decide to accept the risk of energy expenditure, calculating that miner attrition will increase their chances of winning new block rewards. In other words, fewer miners in the network means more chances for the remaining miners to profit. For those adopting this viewpoint, the potential of solving enough blocks to maintain business profitability outweighs the risk of any short-term loss related to high energy costs.

How bitcoin is distributed

Every block consists of many small transactions. When a block is mined, the winning miner is awarded 6.25 bitcoin plus all transaction fees for each transaction they were able to package within the block. The more blocks you are able to solve, the higher your reward. In other words, you get a bigger piece of the pie. Hunger for more slices of pie incentivizes miners to purchase more powerful equipment or move to areas with lower electricity costs.

Game theory and the surety of the Bitcoin network

In a Nash equilibrium, although the individual participants would like to either get more rewards or a different type of reward, they agree to settle with getting something of value rather than nothing. The Bitcoin network compels miners to play by an agreed set of rules to add transactions to the distributed ledger, or their work will be summarily rejected. At the same time miners add security to the network by expending expensive energy that chains each new block to the preceding block via a well established mathematical algorithm.

Each miner is, therefore, a generator of new bitcoin liquidity as well as an auditor, checking the details of network transactions. Even though each problem solved involves a zero-sum game and congestion theory dictates how each miner approaches the task, everyone works in a happy Nash equilibrium.

In the end, game theory is an underestimated, yet essential, element of the Bitcoin network. As each miner plays their role, historical transactions are kept secure and new transactions unanimously approved, which helps maintain Bitcoin’s position as the number one digital currency in the world.

The Most Confusing Economics Concepts Explained: Inflation vs. Deflation

Inflation and deflation are common economic terms that can be a bit confusing. They aren’t always addressed in school, but they affect our lives in so many ways. While the causes and consequences of inflation and deflation can be complicated, their definitions are surprisingly simple. Here is what you should know about these two terms and their role in a greater economy.

What is inflation?

In the simplest terms, inflation occurs when the price of goods and services goes up over time. It can happen slowly, over decades, or with sudden and devastating effects. Not every economist agrees on the reasons for slow, gradual inflation. It’s often tied to factors like market demand or the availability of certain goods and services.

Inflation in action

A current example is the inflated price of backyard swimming pools, pool filters, and pool maintenance supplies. With COVID-19 precautions closing many local swimming pools, more people than ever decided to put up backyard pools this summer. This increase in demand forced the price of pools and supplies up; another factor was the scarcity of some pool supplies since they have traditionally been manufactured in countries that slowed or shut down production due to COVID. The combination of increased demand with a short supply led to a deep inflation in the cost of these goods.

Hyperinflation

There’s more to the story, however. When both the cost of goods goes up, and the value of the local fiat goes down, it’s often referred to as “hyper-inflation,” especially when both happen in a short time frame. Unlike standard inflation, which experts aren’t always able to attribute directly to a source, economists tend to agree on the cause of hyperinflation.

The most common cause is a sudden and excessive growth of a country’s money supply. How does this happen? The Fed usually plays a role in making more money available in a strangled economy. Additionally, it’s not uncommon for governments to step in and tinker with interest rates or offer economic cash infusions (stimulus payments) in an attempt to stop the financial bleed that frequently happens with long periods of hyperinflation. Unfortunately, the bandaids for hyperinflation can often make problems worse.

How can you know if we’re in a period of inflation or hyper-inflation?

While the Fed aims for a rate of 2–3% per year inflation, this isn’t always manageable. Venezuela, for example, has seen inflation rates of 200,000% in a single year, an obvious sign of hyperinflation. It doesn’t have to be that severe to be counted, however; experts define anything above a 50% annual inflation rate to be a form of hyperinflation.

What is deflation?

The exact opposite of inflation, deflation, is the decrease in the cost of goods and services. It is usually accompanied by an increase in the value of the fiat. While some see this as a pleasant situation, deflation can be difficult for lenders who rely on climbing interest rates to make money on the cash they lend. Too much deflation or inflation can hurt essential industries. It can also harm consumer confidence over time, as people can get used to seeing prices go lower and actually hold on to their money waiting for the absolute best price. This can further aggravate the deflation cycle, something we saw during the Recession of 2008.

Remember, the role of government, unemployment, natural disasters, and technological advances can impact the cost of products we buy. Further, in the U.S., inflation doesn’t always happen across the board; consumer categories such as food and housing may see inflation over time, while items like electronics or clothing may see deflation during the same period. While consumers can’t always do much to affect inflation or deflation, we can better prepare our investment portfolios to secure our individual economic futures.

How to Protect Your Anonymity Against Crypto Dusting Attacks

Since Bitcoin’s debut to the public more than a decade ago, supporters have praised the benefits of cryptocurrency transactions including decentralization, transparency and anonymity. While these benefits certainly have their advantages, crypto’s nature also opens you up to a level of risk that has been realized through activities like dusting attacks and airdrops that often go completely unnoticed if crypto holders don’t know what to look for. Fortunately there are steps you can take to protect yourself from malicious entities interested in deanonymizing you. Understanding the nature of dusting attacks and airdropping can help you determine the best way to protect yourself and your crypto holdings from hackers and scammers.

The blockchain: Not as anonymous as you might think

Many people mistakenly think bitcoin is private. It’s anonymous, yes, but not private. A transaction is made up of input(s) and output(s). When you spend, you are creating a transaction using your address as an input. When you receive, your address is given an amount of bitcoin, which becomes the output. All of this transaction information (including the addresses involved, amounts and times of the transactions) are recorded on the blockchain. As that ledger is 100% transparent and public, so are your transactions. Any uninvolved party (people who have not transacted with you directly) examining the blockchain can see the cryptocurrency being received or spent — they just won’t know it’s you spending or receiving it because the owners of the addresses are not revealed. If the person you’re transacting with knows who you are however, they may be able to associate your blockchain wallet (and future transactions) with you, as anonymity only applies when referring to non-involved parties. And even still, a non-involved party may not know who you are from the beginning, but by watching blockchain activity, they may be able to figure it out if your wallet is maliciously “dusted” and use this information to deanonymize you in the future.

Dusting: Revealing your identity, one satoshi at a time

When you use bitcoin to pay for something, one or more addresses (UTXOs) are selected that most closely match the amount due and you receive an output UTXO with your change. For example, if you were paying for something equal to $400 and you had three UTXOs in your wallet equal to $5,000, $5, and $399, you could use the UTXOs equal to $399 and $5 and would receive a UTXO back worth $4. All of this information is recorded on the public ledger.

With dusting, a hacker or scammer sends very small amounts of a cryptocurrency (dust) to a large number of addresses. If you receive dust, you will have a UTXO in your wallet with a very small value. As you spend from your wallet, the attacker watches to see when the dust UTXO is picked up. When it is, they take note of all the other UTXOs that go along with it as well as what addresses they go to. When these entities study transactional patterns long enough, they can eventually identify all the addresses linked to your wallet, which means they can figure out how much crypto you have. If your account is of interest (you have large sums), they can work on figuring out it belongs to you, which can make you a target for anything from scams and phishing campaigns to cyber-extortion threats.

One reason dusting is so insidious is that the amounts of crypto sent to accounts are so very small; they are smaller than the minimum transaction fee required to use cryptocurrency. Most times, the dusting amounts are calculated in units known as satoshis; one satoshi equaling 0.00000001 bitcoin. Given the minuscule size of dust, the chances are pretty good that many people won’t notice them as they casually scan their cryptocurrency total.

Airdropping: Free tokens, potential scams

Airdropping is similar to dusting in that it adds small amounts of crypto to your wallet. But airdropping’s purpose is far less ominous. Companies that airdrop want to use you to spread the word about their great new cryptocurrency. As such, they will send free coins or tokens to your address (found on the public blockchain). Sometimes they send them free and other times they ask for something in return (like a tweet about the company and its currency). You might also actively encourage airdrops to your wallet in hopes that the new cryptocurrency will ultimately have a large payout. There are hundreds of airdrop lists and websites, all eager for your interest.

While the purpose of airdrops is often benign, problems come up when hackers and scammers reach out for more than your public wallet address. If you aren’t careful, you could be at risk from the following:

Protect your crypto from malicious dusting and airdrop attacks

Because cryptocurrency transaction information is public knowledge, it’s important to protect yourself, your holdings and your anonymity. In addition to ensuring anti-spam and anti-viral protection for your wallet, consider the following steps.

If you think you’ve been dusted, don’t move the dust. Look for wallet apps that allow you to “mark” small, unknown deposits in your wallet to prevent them from being used for other transactions.

Monitor your balance — 100% of the time. If wayward satoshis suddenly show up in your cryptowallet, you might have been dusted. It’s a good idea to find a wallet app with a push notification, which tells you when you receive new funds.

Don’t give out private information — ever. If a website — or other airdrop entity — wants more than your wallet address in exchange for tokens or coins, it’s a red flag. Be as wary of handing out your cryptocurrency information as you would be of providing fiat bank account log-in data.

Keep your anonymity in place

None of the above is meant to suggest that cryptocurrency trading or usage is dangerous. It is, however, a reminder that while transactions can be anonymous (when actually conducting a transaction you may potentially be revealing information about who you are to complete it, which can then be associated with your wallets), they aren’t private. Unfortunately, scammers and hackers are taking advantage of the very public blockchain technology to determine the identities of those behind cryptocurrency transactions.

The good news is that knowledge is power. You can protect yourself from malicious entities and preserve your anonymity by being aware of attacks like dusting and taking preventative action. Doing so will better protect you and your holdings while helping to ensure you don’t become victim to phishing or cyberextortion threats.

What to Expect When the Value of Your Collateral is on the Decline

Your collateral is what protects your loan. It’s why SALT doesn’t need to perform income checks or credit checks when issuing a loan. But cryptocurrencies are volatile, so what happens if the value of your collateral begins to fall? Declining collateral value negatively impacts your Loan-to Value-Ratio (LTV) — that is the amount of outstanding principal still owed on your loan divided by the value of your underlying collateral: Outstanding Principal / Value of Collateral. LTV is the key metric SALT uses to determine the health of a loan. The lower the LTV, the healthier the loan. If the value of your collateral goes up, your LTV goes down. If the value of your collateral goes down, your LTV goes up. It’s that simple.

Choosing your Loan-to-Value (LTV)

When choosing your LTV, the most important consideration is your risk tolerance. We offer starting LTV options of 30%, 40%, 50%, 60%, and 70%. If you go with a 30% LTV, you are choosing the safest level of overcollateralization, or cushion. With a 70% LTV, you won’t have to deposit as much crypto to begin with, but you’ll have the least amount of cushion. The higher the starting LTV, the higher the risk. Choose the LTV option that’s right for you.

What can you expect from us when your collateral declines in value and your LTV begins to rise? Lots of notifications.

If your collateral continues to go down in value, your LTV will steadily climb. As your LTV crosses certain critical thresholds (75%, 83%, 88%, and 90.91% as of the time of this writing) SALT’s robust monitoring and notification technology kicks in to help protect your loan.

After all, lenders wouldn’t be willing to lend the money in the first place if SALT couldn’t guarantee its safety.

How you respond to a rising LTV and warning notifications is up to you. Here are the current options:

We’ve done the math to show you how each of these options impacts your assets, remaining principal, and required payment.

Based on the above calculations, if you want to avoid any loss of assets, it’s best to respond as quickly as possible with options one or two. Otherwise, option three is available if that’s what you prefer. Either way it’s important to think through the options and know where you stand before your LTV crosses our liquidation threshold.

Keep tabs on your loan health from anywhere via the real-time LTV widget on your web dashboard or by logging into your account through our mobile app.

It’s on us to monitor your loan health and keep you updated. It’s on you to take action (or not take action) when your collateral value is on the decline.

Loan to Value (LTV) Explained

When you apply for a traditional loan, the lender uses your credit score, as reported by third-party credit agencies, to determine your credit worthiness or financial “reputation.” The higher your credit score, the lower the risk. To offset your credit score or in some cases even completely remove it from the equation, you can apply for an asset-backed loan. With this type of loan, you can offer up your assets — anything from your house or car to your stock portfolio — as collateral to act as “insurance” for the lender. In asset-backed lending, borrowers typically secure loans for an amount that’s less than the total value of the collateral.

The measurement of the balance of the loan relative to the value of the collateral asset is represented as loan-to-value or LTV. For example, you may have a loan for $320,000 for a home that is valued at $400,000, in which case your loan is 80% of the total value of the home.

As an asset-backed lender, one of the things that makes SALT unique is that we don’t even look at your credit score. With a SALT loan when you have collateral — whether you’re unbanked, haven’t accumulated credit, or have poor credit — you can still get a loan. Instead, SALT uses loan-to-value of your collateral to assign risk. As LTV is a measure of risk, the lower the LTV, the lower the risk for the lender (and therefore the lower the interest rate for the borrower).

How is LTV calculated?

Good question.

LTV is calculated as the loan amount in USD divided by the value of the collateral in USD, expressed as a percentage.

As an example, if you have a current loan balance of $100,000 and your total collateral asset balance is $200,000, you have an LTV of 50%. To make things easier, we’ve added an LTV Helper to the borrower portal that illustrates exactly how the LTV is calculated. See below.

Understanding LTV and how it’s calculated is essential to making an informed decision about your loan terms. Liquidation events benefit no one, which is why we provide the tools like our automated notification system to help you avoid them. Before you apply for a loan, you should ask yourself:

Once you answer these questions, you can choose the LTV that’s right for you.

Starting LTV

When you are taking out a loan against your crypto assets with SALT, you presently have 3 options for your starting LTV; 30%, 40% and 50%. The starting LTV will determine approximately how much (in terms of dollars) of the crypto asset you will need for that loan.

From the example above, for a $100,000 loan, you would need $200,000 in Bitcoin, Ether, Doge, or Litecoin to secure the 50% LTV loan option. For a 40% LTV, it would be $250,000 and for 30% LTV, it would be approximately $333,333.

Using LTV as a measure of risk, the 30% LTV option is the lowest risk.

Why is a lower LTV seen as less risk?

As the LTV goes up, the value of the underlying asset goes down. In the case of a crypto asset-backed loan, the value of Bitcoin, Ether, Litecoin, or Doge is trending down.

If the price of the crypto asset falls too low, the LTV will continue to increase. As it approaches 100%, there is a threshold where the collateralized asset will be sold to pay back the loan. This is known as the liquidation threshold. This threshold can vary from business to business and loan to loan.

For our example, let’s say the liquidation threshold is set to a 90% LTV.

When the LTV ratio reaches 90%, the crypto asset will be sold to reduce the LTV back down.

Timeout. Liquidations!?!

At SALT, we pride ourselves in having a robust notification system that relays important account activity to borrowers via our portal, text, phone calls, and emails. We give you control of how you want to be notified about each activity. You can be notified of everything from deposits and withdrawals to LTV warning thresholds.

As a borrower, you always have the option to transfer more collateral at any time.

Back to LTVs.

Why does this matter?

As you might be aware, the price of Bitcoin (or any crypto asset) can move up and down. As the price moves up, your LTV goes down. As the price moves down, your LTV goes up.

To build on our earlier example of a $100,000 loan with a 50% LTV, let’s use Bitcoin as the underlying crypto asset. In this example, let’s use $4,000 as the US dollar price of 1 Bitcoin.

Loan Amount = $100,000

Starting LTV = 50%

Price of 1 Bitcoin = $4,000

Doing the math $200,000/$4,000, you would need approximately 50.00 BTC to get a $100,000 loan with a 50% starting LTV.

Bringing it all together!

From above, assuming the liquidation threshold is set at 90% LTV, the price of 1 Bitcoin would need to go all the way down to approximately $2,222 to raise the LTV up to the liquidation threshold of 90% LTV.

A $100,000 loan with a starting LTV of 40%, would require 62.50 BTC at a price of $4,000 per Bitcoin. However, the 90% liquidation threshold would not be reached until the price of 1 Bitcoin went down to approximately $1,778.

Repeating the example with a 30% LTV, you would need 83.33 BTC at a price of $4,000 per Bitcoin and would reach the 90% liquidation threshold when the price of 1 Bitcoin was approximately $1,333.