Crypto glossary

An airdrop is a free distribution of tokens to a set of wallet addresses, usually to reward early users or spread ownership of a new project. It matters because it can turn ordinary activity like swapping tokens or testing an app into a payout, though it also invites bots and requires care with scam links. For example, in September 2020 Uniswap gave 400 UNI tokens to every address that had used the protocol before that date, worth several thousand dollars at the time. Airdrops can be announced ahead of time or dropped as a surprise after the fact, and eligibility rules vary widely between projects.

A bridged token is a representation of an asset from one blockchain that's been moved to another chain through a bridge, usually locked on the original chain while a matching version gets minted elsewhere. This matters because the bridged version isn't the same asset in a legal or technical sense; it's an IOU backed by whatever the bridge operator holds, so its safety depends entirely on that bridge's security. For example, when you move ETH from Ethereum to Arbitrum, you don't get "real" ETH on Arbitrum. You get a bridged version that Arbitrum's contracts treat as ETH, redeemable back to the original only if the bridge stays solvent and uncompromised. Several bridge hacks, including the $625 million Ronin exploit in 2022, wiped out bridged tokens even though the underlying originals were untouched.

Circulating supply is the number of coins actually trading in the market right now, while fully diluted supply (FDV) counts every coin that will ever exist once all vesting, mining, or unlock schedules finish. The gap between the two matters because a low circulating supply can make a coin's price look cheap while a huge future unlock waits to flood the market and pressure that price down. For example, a token might show a $50 million market cap with only 5% of coins circulating, but a fully diluted valuation of $1 billion once the remaining 95% unlocks over the next three years. Checking both numbers before buying tells you whether early holders and insiders are sitting on supply that could hit the market later, diluting your share of the network.

Custodial means a third party holds your private keys and controls your crypto; non-custodial means you hold the keys yourself. This distinction decides who can actually move your funds if something goes wrong, whether that's a hack, a frozen account, or a company going bankrupt. When Celsius collapsed in 2022, users with funds on the custodial platform got stuck in bankruptcy court for over a year, while anyone holding coins in a non-custodial wallet like a Ledger kept full access the entire time. Custodial setups, like leaving coins on Coinbase, are convenient and offer password resets. Non-custodial wallets, like MetaMask or a hardware device, remove that convenience but also remove the middleman, meaning you alone are responsible for backing up your seed phrase.

A depeg happens when a stablecoin or pegged asset drifts away from the value it's supposed to track, usually $1. Readers care because stablecoins are meant to be the boring, stable part of crypto, and a depeg can wipe out savings fast or signal deeper trouble at the issuer. In May 2022, TerraUSD (UST) fell from $1 to a few cents within days as its algorithmic backing collapsed, dragging its sister token Luna down with it. Smaller depegs happen too: USDC briefly dropped to about $0.87 in March 2023 after news that some of its reserves sat at the failed Silicon Valley Bank, then recovered once regulators guaranteed deposits.

What is an ETP? An exchange-traded product is a security that trades on a stock exchange like a regular share but tracks the price of an underlying asset, such as bitcoin, gold, or a basket of stocks. ETPs matter to crypto readers because they let you get price exposure to an asset through a normal brokerage account, without setting up a wallet or managing private keys. ETFs, ETNs, and exchange-traded commodities are all types of ETP, differing mainly in how they're structured legally and who bears the credit risk. For example, BlackRock's iShares Bitcoin Trust (IBIT) is an ETP that holds actual bitcoin and lets investors buy shares tracking its price on the Nasdaq, the same way they'd buy shares of Apple.

Liquid staking lets you stake a proof-of-stake coin while keeping a tradable token that represents your staked position. It matters because normal staking locks up your coins for days or weeks, and this way you can still use that value elsewhere, like as collateral for a loan, without waiting through an unbonding period. For example, when you stake ETH through Lido, you get stETH in return; it earns staking rewards and can be swapped or deposited into DeFi protocols like Aave at any time, even though your original ETH is still locked with validators. The main risk is that the token can trade below the value of the underlying coin if too many people rush to exit at once.

Liquidation is when an exchange forcibly closes a trader's leveraged position because losses have eaten through the margin backing it. It matters to anyone trading with borrowed money since it can wipe out a position in seconds, often at a worse price than expected due to slippage and fees. For example, a trader opens a $1,000 long on Bitcoin at 10x leverage, controlling $10,000 worth of BTC. If Bitcoin's price drops about 10%, the exchange automatically sells the position to cover the loan, and the trader's original $1,000 is largely or fully gone. Large liquidation waves can also cascade, pushing prices down further as forced selling triggers more liquidations, which is why sudden market crashes sometimes look sharper than the news driving them.

A market maker is a trader or firm that continuously places both buy and sell orders for an asset, profiting from the small gap between the two prices. This keeps exchanges liquid, so regular traders can buy or sell quickly without moving the price much. Without them, order books would be thin and prices would swing wildly on small trades. For example, a firm might post a bid to buy Bitcoin at $64,980 and an ask to sell at $65,020, earning the $40 spread each time both orders fill, while doing this thousands of times a day across many pairs. Many exchanges pay market makers reduced fees or rebates to encourage this constant quoting, since it directly improves trading conditions for everyone else on the platform.

MEV is the extra profit a block producer can make by choosing the order, inclusion, or exclusion of transactions in a block, beyond normal fees and rewards. It matters to readers because it quietly taxes ordinary trades: the price you see isn't always the price you get once someone reorders transactions around yours. A common example is a sandwich attack, where a bot spots your pending Uniswap swap, buys the same token right before it to push the price up, lets your trade execute at the worse price, then sells immediately after for a quick profit. Researchers have tracked well over $1 billion in extracted MEV on Ethereum since 2020. Tools like Flashbots try to make this process more transparent and less harmful to regular users.

What is MiCA regulation? MiCA, short for Markets in Crypto-Assets, is the European Union's rulebook for crypto companies, setting licensing, disclosure, and consumer protection standards across all 27 member states.

It matters because it replaces a patchwork of national rules with one set of requirements, so a company licensed in one EU country can operate in the rest without reapplying. Readers often want to know who it covers: mainly exchanges, wallet providers, and stablecoin issuers, not individual token holders.

MiCA took full effect in December 2024. Under it, stablecoin issuers like Circle must hold reserves and get authorized by an EU regulator, while exchanges need a license to offer trading services to EU residents. It doesn't yet cover NFTs or DeFi protocols directly.

On-chain means an action is recorded directly on a blockchain's public ledger, while off-chain means it happens elsewhere, like a private server or a second layer, without being written to that ledger immediately or at all. This distinction matters because on-chain data is verifiable by anyone but costs more and moves slower, while off-chain data is cheaper and faster but requires trusting whoever runs it. For example, swapping tokens on Uniswap settles on-chain with a public transaction hash, but a Coinbase trade between two users often just updates the exchange's internal database, going on-chain only when funds are withdrawn. Layer-2 networks like Arbitrum process transactions off-chain in batches, then post summaries back to Ethereum for security.

Perpetual futures are derivative contracts that let traders bet on an asset's price with leverage but never expire, unlike traditional futures with a set settlement date. This matters because it's how most crypto traders take large directional bets or hedge positions without ever touching the underlying coin, and it's where a huge share of daily trading volume actually happens. To keep the contract price tied to the spot market, exchanges use a "funding rate," a periodic payment between long and short traders. On Binance, a trader could open a $10,000 long position on BTC perpetuals using just $1,000 of margin at 10x leverage, paying or receiving funding every eight hours depending on which side is crowded.

Proof of reserves is a way for a crypto exchange or custodian to show it actually holds the assets it says it's holding on behalf of customers. It matters to depositors because it offers some evidence against the risk of a platform lending out or losing customer funds without telling anyone. Typically an exchange publishes wallet addresses and a cryptographic snapshot of balances, sometimes paired with a Merkle tree so users can check their own account is included in the total. For example, after FTX collapsed in November 2022, several exchanges including Binance and Kraken published proof of reserves reports showing Bitcoin and Ethereum holdings matched or exceeded customer balances. It's not a full audit though: it usually skips liabilities, so it can't rule out hidden debts sitting alongside the reserves.

A realized gain is profit you've locked in by selling an asset, while an unrealized gain is profit on paper for a position you still hold. This distinction matters because taxes usually apply only when you sell, and unrealized gains can vanish if prices reverse before you cash out. For example, if you bought 1 ETH at $1,800 and it's now worth $3,200, you have an unrealized gain of $1,400. Sell it, and that $1,400 becomes realized and taxable. Hold instead, and a price drop to $2,000 shrinks your paper profit to $200 without you ever seeing the higher number in your wallet. Traders track both figures separately to plan tax bills and avoid confusing portfolio hype with actual cash in hand.

Restaking lets you reuse crypto you've already staked to secure a blockchain so it also secures other services, like oracles or bridges, at the same time. It matters because it can earn you extra yield on the same capital, but it also stacks new risks: if one of those extra services gets hacked or slashed, your original stake can take the hit too. EigenLayer popularized the idea on Ethereum, letting people restake staked ETH (or liquid staking tokens like stETH) to back things like data availability layers, earning added rewards on top of normal staking yield, currently often single-digit percentages, in exchange for taking on that added slashing risk.

A spot Bitcoin ETF is a fund traded on a regular stock exchange that holds actual Bitcoin and tracks its current market price. It lets investors gain exposure to Bitcoin through a normal brokerage account, without setting up a crypto wallet or managing private keys. This matters because it opens Bitcoin to retirement accounts, financial advisors, and everyday investors who'd never touch a crypto exchange. In January 2024, the SEC approved 11 spot Bitcoin ETFs at once, including BlackRock's IBIT and Fidelity's FBTC. Unlike a futures-based ETF, which holds contracts betting on Bitcoin's future price, a spot ETF must actually own the coins backing each share, so its price tracks Bitcoin more closely.

What is a stop loss? It's a standing order that automatically sells an asset once its price falls to a level you set in advance, capping how much you can lose on a trade. It matters because crypto markets move fast, and a stop loss protects you from a bad position turning into a disaster while you're asleep or away from your screen. Say you buy ETH at $3,000 and set a stop loss at $2,700. If the price drops to $2,700, the order triggers and sells automatically, limiting your loss to 10% instead of riding the price down further. One follow-up worth knowing: in thin or fast-moving markets, your order may fill below your stop price, a gap called slippage.

Tokenomics is the design of a crypto token's supply, distribution, and incentives: how many exist, who gets them, and what makes people want to hold or use them. It matters because these rules shape whether a token's price reflects real demand or just early insiders cashing out. For example, Bitcoin's tokenomics cap supply at 21 million and cut new issuance in half roughly every four years, which is why the "halving" gets so much attention. Contrast that with a token that mints 40% of its supply to the founding team with a one-year lock-up: that setup tells you a lot about likely sell pressure once the lock-up ends. Reading a project's tokenomics before its marketing is usually the faster way to spot the actual incentives at play.

A bitcoin node is a computer running software that checks every transaction and block against Bitcoin's rules, then relays valid data to other nodes on the network. It matters because nodes, not miners, decide what counts as valid bitcoin. Running one lets you verify your own balance and transactions without trusting a company or exchange to tell you the truth.

The most common setup is a "full node," like Bitcoin Core, which downloads the entire blockchain (over 600GB as of 2024) and independently checks each block's rules before accepting it. Miners propose blocks, but if a block breaks the rules, nodes reject it regardless of how much mining power backed it. Anyone can run a node on a home computer or a small device like a Raspberry Pi, and thousands of volunteers do, which is what keeps Bitcoin decentralized rather than controlled by a handful of large players.

A block explorer is a website or app that lets you search a blockchain's public ledger to see transactions, wallet balances, and block details. It matters because anyone can verify a payment actually happened without trusting a bank or exchange to confirm it. Say you send 0.01 BTC to a friend. You copy the transaction ID into a site like mempool.space or blockchain.com's explorer, and it shows the amount, sender and receiver addresses, how many confirmations it has, and the fee paid.

Most explorers also let you look up any wallet address to see its full history and current balance, which is why people are careful about reusing addresses if they want privacy. Ethereum has its own explorer, Etherscan, which additionally shows smart contract code and token transfers, since Ethereum tracks more than simple coin sends.

A blockchain oracle is a service that feeds outside data, like prices, weather, or sports scores, into a blockchain so smart contracts can use it. Blockchains can't fetch information on their own, so contracts that depend on real-world facts need an oracle to bring that data in reliably. This matters because a lot of DeFi runs on data accuracy: a lending app needs to know ETH's current price to decide when to liquidate a loan. Chainlink is the best-known example, pulling price feeds from multiple independent sources and averaging them so no single bad data point can trigger a wrong liquidation. Oracles are also a weak point: if the data feed gets manipulated, attackers can drain funds, which is why many protocols use several oracles and check for outliers before trusting a number.

A cold wallet is a device or piece of paper that stores crypto private keys completely offline, away from any internet connection, so hackers can't reach them remotely. This matters because most crypto theft happens through online exploits, and keeping keys offline removes that entire attack surface for savings you don't touch daily. A common example is a Ledger or Trezor hardware wallet costing $60-$150, where you approve transactions by pressing a physical button on the device itself.

The follow-up question people usually have: how do you actually use it if it's offline? You plug the device in only when signing a transaction, then disconnect it. The signed transaction broadcasts through your regular internet-connected computer, but the private key itself never touches that computer or the web.

A crypto custodian is a regulated company that holds and secures digital assets on behalf of clients, managing the private keys so the owner doesn't have to. This matters because losing a private key means losing the funds forever, and most institutions can't legally or practically self-custody at scale. Custodians add insurance, audits, and multi-signature controls that individual wallets typically lack.

A reader's next question is usually how this differs from an exchange holding coins. Exchanges custody assets as a side effect of letting you trade; dedicated custodians make security their entire business. Coinbase Custody, for example, holds billions in institutional assets in offline "cold storage" and carries insurance against theft. Pension funds and ETFs buying Bitcoin almost always use a third-party custodian rather than holding keys themselves.

A governance token is a crypto asset that gives holders voting rights over a protocol's rules, like fee levels, treasury spending, or software upgrades. It matters because it shifts control from a founding team to whoever holds the most tokens, which can mean broader input or just concentrated power in different hands.

Voting usually happens on-chain through a proposal system: holders lock or delegate tokens to vote yes or no, and outcomes execute automatically once a quorum passes. Uniswap's UNI token, for example, let holders vote in 2022 on whether to deploy the protocol to BNB Chain.

The follow-up question worth asking: does holding the token actually change outcomes, or do a few whales and venture funds control most votes? Many governance systems look decentralized on paper but concentrate real power in a small number of large wallets.

A hard fork is a permanent split in a blockchain's rules that makes new blocks incompatible with old software, forcing every node to upgrade or get left behind. It matters because forks can create entirely new coins, change core economics, or fix bugs, and holders sometimes wake up owning assets on two separate chains. Bitcoin's 2017 split into Bitcoin (BTC) and Bitcoin Cash (BCH) happened because developers disagreed over block size limits; anyone holding BTC before the fork ended up with equal BCH too. The natural next question is whether a hard fork is risky: it can be, since it splits the network's security and community, and old nodes that don't upgrade get stuck on an abandoned chain. Not every fork creates a new coin though; some, like Ethereum's regular protocol upgrades, are backed by near-universal consensus and cause no split at all.

A hardware wallet is a small physical device that stores your crypto private keys offline, signing transactions without ever exposing those keys to an internet-connected computer. It matters because most crypto theft happens through hacked exchanges or malware on a phone or laptop, and keeping keys offline removes that entire attack surface. A reader's next question is usually how it differs from a software wallet: a hardware wallet like a Ledger Nano X or Trezor Model One requires you to physically press a button to approve each transaction, so malware can't silently drain funds. You still need to back up the recovery phrase, usually 12 or 24 words, written on paper and stored somewhere safe. Lose both the device and that phrase, and the funds are gone for good.

A hot wallet is a crypto wallet that stays connected to the internet, letting you store, send, and receive coins directly from an app or exchange account. It matters because that connection makes hot wallets convenient for everyday spending and trading but more exposed to hacking than offline storage. The natural follow-up: should you keep everything there? Most people keep a small working balance in a hot wallet, like $200 in MetaMask for buying NFTs or swapping tokens, and move larger holdings to a cold wallet, a device disconnected from the internet, for safekeeping. Exchange accounts on Coinbase or Binance are also hot wallets by this definition, since the platform controls keys tied to an online server. Losing your password or falling for a phishing link is the main risk with any hot wallet.

A limit order is an instruction to buy or sell an asset at a specific price or better, rather than whatever the current market price happens to be. It matters because it gives you control over your entry or exit price, protecting you from slippage during fast-moving or thin markets. The tradeoff is that a limit order might never fill if the market never reaches your price.

For example, if Bitcoin trades at $60,000 and you set a buy limit order at $58,000, the trade only executes if the price drops to $58,000 or lower. If it stays above that, your order sits unfilled on the exchange's order book. This contrasts with a market order, which fills immediately at whatever price is available, sacrificing price control for speed.

A liquidity pool is a shared pot of two or more tokens locked in a smart contract so traders can swap between them without needing a matching buyer or seller. Instead of an order book, prices move based on a formula tied to how much of each token sits in the pool. This matters because it lets anyone trade or earn fees on decentralized exchanges like Uniswap, even for obscure tokens with few active traders. People who deposit tokens are called liquidity providers, and they earn a cut of trading fees in return. For example, a USDC/ETH pool on Uniswap might hold $2 million in each asset; every swap through it charges a small fee, often 0.3%, split among everyone who supplied funds. The main risk providers face is impermanent loss, when the price ratio between the two tokens shifts after depositing.

A mempool (memory pool) is the waiting area on a node where unconfirmed transactions sit until a miner or validator picks them up and adds them to a block. It matters because how full the mempool is drives the fee you need to pay: a crowded mempool means higher competition for block space and pricier transactions, while an empty one means cheap, fast confirmation. Every node keeps its own version, so the exact set of pending transactions can differ slightly node to node. For example, during the May 2022 Bitcoin fee spike, the mempool held over 100,000 unconfirmed transactions, pushing average fees past $6 as users bid to jump the queue. Tools like mempool.space let anyone watch this queue in real time.

A multisig wallet is a crypto wallet that needs approval from more than one private key before it can send funds, spreading control across multiple people or devices. This matters because it removes the single point of failure you get with a normal wallet: if one key is lost or stolen, the funds stay safe as long as the others are secure. Setups are often described as "M-of-N," meaning M signatures are required out of N total keyholders. For example, a 2-of-3 multisig might split keys between a founder, a co-founder, and a lawyer, so any two must agree before a transaction goes through. Companies use multisig to manage treasuries, and individuals use it to guard against a single lost hardware wallet wiping out their savings. Gnosis Safe is a common tool for setting one up on Ethereum.

A satoshi is the smallest unit of bitcoin, equal to one hundred-millionth of a single BTC (0.00000001 BTC), named after bitcoin's pseudonymous creator Satoshi Nakamoto.

It matters because bitcoin's price per coin can run into tens of thousands of dollars, so satoshis (often shortened to "sats") let people price, tip, and transact in amounts far smaller than a whole coin without dealing with long strings of decimals. Traders and app builders often quote fees or balances in sats for the same reason cents are more practical than fractions of a dollar.

For example, if 1 BTC trades at $60,000, one satoshi is worth $0.0006, and 1,000 sats would be worth about $0.60. Lightning Network payments, a fast bitcoin payment layer, are typically denominated in sats rather than BTC.

An altcoin is any cryptocurrency other than Bitcoin, short for "alternative coin." The term matters because it groups thousands of very different projects, from Ethereum's smart contract platform to small meme tokens, under one label, so it's worth checking what a coin actually does before assuming "altcoin" tells you anything about quality or risk. Ether, Solana, and Dogecoin are all altcoins despite having almost nothing in common beyond not being Bitcoin. Some altcoins power blockchains with real transaction volume; others exist mainly for speculation. Traders often watch "alt season," a stretch when altcoins rise faster than Bitcoin, as a sign that risk appetite in the market is increasing. Because the category is so broad, comparing an altcoin's market cap, use case, and team is more useful than treating the label itself as a signal.

An order book is a live list of buy and sell orders for an asset, showing the prices and amounts traders want to trade at. It matters because it shows real supply and demand, not just a single price, so you can gauge how easy it is to buy or sell without moving the market. The book has two sides: bids (buy orders) stacked below the current price, and asks (sell orders) stacked above it. The gap between the highest bid and lowest ask is the spread. On Binance's BTC/USDT book, you might see a $500,000 bid wall at $60,000 and a thinner ask side above $60,050, hinting buyers are more eager than sellers right now.

Impermanent loss is what is impermanent loss, in short: the drop in value a liquidity provider sees when the prices of the two tokens they deposited in a pool move apart, compared to just holding them separately. It matters because pool rewards and fees can still leave you worse off than simple holding once you account for this gap.

Say you deposit $500 of ETH and $500 of USDC into a pool. If ETH doubles in price, arbitrage trades rebalance the pool, and you end up with less ETH and more USDC than before, worth less than if you'd held the original $1,000 in ETH and USDC untouched.

The loss is "impermanent" only if prices return to their original ratio; if you withdraw while they're still apart, it becomes permanent and real.

What is KYC crypto? It's the identity check exchanges run before letting you trade, and AML (anti-money laundering) is the broader set of rules those checks support to stop illegal funds from moving through the system. This matters because it decides how much personal data you hand over and whether an exchange freezes withdrawals if something looks off. Coinbase, for example, asks new users for a government ID and a selfie before they can buy Bitcoin, then monitors transactions for patterns like rapid transfers to unhosted wallets. The follow-up most people ask: can you avoid it? Decentralized exchanges like Uniswap don't require KYC, but banks and regulated on-ramps almost always do, and regulators are pushing to close that gap through rules like the EU's MiCA framework.

Leverage trading crypto means borrowing funds from an exchange to open a position bigger than your own account balance, using your deposit as collateral. It matters because it magnifies both gains and losses, so a small price move against you can wipe out your entire deposit fast. The follow-up question most people have: what happens when you lose? If the market moves past a set point, the exchange automatically closes your position through liquidation, keeping your remaining collateral as loss coverage.

For example, with 10x leverage and $100, you control a $1,000 position. A 10% price drop against you would erase the full $100, triggering liquidation, while a 10% gain would double your money. Most exchanges show your liquidation price before you confirm the trade.

A wrapped token is a version of one cryptocurrency issued on a different blockchain, backed one-to-one by the original coin held in reserve. It matters to a reader because it lets assets like Bitcoin work inside ecosystems, such as Ethereum's DeFi apps, that wouldn't otherwise recognize them. For example, Wrapped Bitcoin (WBTC) is an ERC-20 token on Ethereum: a custodian holds real BTC in a vault, and for every BTC deposited, one WBTC gets minted. Trading WBTC lets someone use Bitcoin's value in a Uniswap pool or as loan collateral on Aave. The catch is trust in whoever holds the reserves; if that custodian gets hacked or acts dishonestly, the wrapped token can lose its backing and its peg to the original asset.