Bitcoin glossary

70+ Bitcoin and crypto terms — protocol, technical analysis, on-chain metrics, trading and wallets — defined in plain English. Each term has a permalink, so you can share /learn/glossary#term directly.

A

Address Wallet #: A string of letters and numbers used to receive Bitcoin. Mathematically derived from a public key. Modern Bitcoin uses three main formats: legacy (starts with 1), SegWit (starts with 3 or bc1q) and Taproot (bc1p). Anyone can see an address; only the matching private key can spend from it.
Altcoin Trading #: Any cryptocurrency that isn't Bitcoin. Ethereum, Solana, XRP, Dogecoin etc. The term lumps together thousands of very different protocols and trade-offs — useful only as a casual category, not as an investment thesis.
All-time high (ATH) Trading #: The highest USD (or quote-currency) price an asset has ever traded at. Bitcoin's all-time highs have anchored every cycle's psychology — the months before a new ATH typically run on extreme greed, the years after the previous ATH was set typically run on doubt and fear.
All-time low (ATL) Trading #: The lowest price an asset has ever traded at. For Bitcoin: about $0.0008 in 2010 on the first-ever exchange listings.

B

Bear market Trading #: A sustained period of declining prices, conventionally a drop of 20% or more lasting several months. For Bitcoin, bear markets have historically run 12–18 months and dropped price 60–85% from the prior cycle's top.
Bitcoin (BTC) Protocol #: A peer-to-peer digital currency and the network that runs it, launched in January 2009 by an anonymous developer using the name Satoshi Nakamoto. Capped at 21,000,000 coins ever issued. The first successful implementation of a decentralised digital currency.
Block Protocol #: A bundle of confirmed Bitcoin transactions, cryptographically linked to the previous block. A new block is added to the chain roughly every 10 minutes by the miner that solves the proof-of-work puzzle. The current block size cap is ~4 MB of "weight" (introduced by SegWit).
Block reward Protocol #: The newly-minted BTC paid to the miner that produces a block, plus all the transaction fees in that block. After the April 2024 halving the subsidy portion is 3.125 BTC. Halves every 210,000 blocks (~4 years). Drops to zero by ~year 2140.
Block time Protocol #: The interval between two consecutive blocks. Targeted at 10 minutes via the difficulty adjustment, but real averages are typically 9.5–9.8 minutes because hashrate grows faster than difficulty catches up.
Bollinger Bands TA #: A volatility envelope drawn at ±2 standard deviations around a 20-period moving average. Price tends to mean-revert toward the centre band; touching the upper band signals overextension, touching the lower band signals oversold. The %B indicator quantifies position within the bands: 0 = lower band, 1 = upper band.
Bull market Trading #: A sustained period of rising prices. For Bitcoin, bull markets have classically followed the halving and run 12–18 months, peaking at the new cycle's ATH.

C

CBBI On-chain #: The Colin Talks Crypto Bitcoin Bull Run Index — a 0–100 composite that averages 9 cycle indicators (Pi Cycle Top, MVRV Z-Score, Puell Multiple, RHODL, Reserve Risk and others). Scores below 15 have marked every major BTC bottom since 2013; scores above 80 have coincided with major distribution phases.
Coinbase transaction Protocol #: The very first transaction in every block — the one that pays the miner the block reward. Not to be confused with the Coinbase exchange. The famous Genesis Block's coinbase transaction contains the embedded message "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks".
Cold wallet Wallet #: A Bitcoin wallet whose private keys never touch an internet-connected device. Hardware wallets (Ledger, Trezor, Coldcard) are the standard cold storage tool. Trade-off: maximum security, slightly slower to spend from.
Confirmation Protocol #: The number of blocks added to the chain after the block containing your transaction. Most exchanges and merchants treat 3–6 confirmations as final; for very large amounts, some wait 100. More confirmations = exponentially harder to reorg.
Custodial vs non-custodial Wallet #: Custodial: someone else (an exchange, a custodian) holds the private keys for you. You access funds via a login. Convenient, but if the custodian fails (Mt. Gox, FTX, Celsius), your funds can be lost. Non-custodial: you hold the keys. The phrase "not your keys, not your coins" refers to this distinction.

D

Dollar-Cost Averaging (DCA) Trading #: Investing a fixed amount on a fixed schedule (e.g. $100 every Monday) regardless of price. Reduces timing risk vs lump-sum buying — see our DCA calculator for a full historical back-run.
Diamond hands Slang #: A trader who holds through volatility and panic. Counterpart to paper hands. Emoji: 💎🙌.
Difficulty Protocol #: The hardness of the proof-of-work puzzle miners are solving to find the next block. Adjusts every 2016 blocks (~2 weeks) so that the average block time stays near 10 minutes — if hashrate grew, difficulty goes up; if it dropped, difficulty goes down.
Divergence (bullish / bearish) TA #: When price prints a new high or low but a momentum indicator (RSI, MACD) doesn't follow. Bearish divergence: price higher high, RSI lower high — momentum fading. Bullish divergence: price lower low, RSI higher low — selling pressure exhausting. Most reliable on daily and above.
Drawdown Trading #: The percentage drop from a peak. "Maximum drawdown" is the largest peak-to-trough fall over a period. Bitcoin's largest single drawdown was about 94% from June 2011 to November 2011; the biggest in the modern era was about 85% from December 2017 to December 2018.

E

EMA — Exponential Moving Average TA #: A moving average that gives more weight to recent prices, reacting faster than a simple moving average. Common periods on Bitcoin: EMA 20 (short trend), EMA 50 (medium), EMA 200 (long-term regime). Price above EMA 200 ≈ bull regime; below ≈ bear regime.
Epoch Protocol #: The period between two halvings — 210,000 blocks, roughly 4 years. Bitcoin is currently in epoch 5 (post-April 2024 halving). Each epoch has a fixed block subsidy that's half the previous epoch's.
Exchange (CEX / DEX) Trading #: A platform for buying / selling crypto. CEX (centralised exchange) = Bybit, Kraken, Coinbase — fast, custodial, requires KYC. DEX (decentralised exchange) = non-custodial, runs on smart contracts (Uniswap on Ethereum, Bisq for Bitcoin). DEXs are less common for pure BTC trading because Bitcoin lacks native smart contracts.

F

Fear & Greed Index On-chain #: A 0–100 sentiment score published by Alternative.me. Aggregates BTC volatility, market momentum and trading volume, social media mentions, Bitcoin dominance and Google Trends. 0 = extreme fear, 100 = extreme greed. Full explainer →
Fee (sat/vB) Protocol #: What you pay miners to include your transaction in a block, quoted in satoshis per virtual byte. Higher fee = sooner confirmation. Mempool congestion drives the going rate — during the 2024 Runes mania, fees briefly spiked over 1000 sat/vB. Full explainer →
FOMO / FUD Slang #: FOMO = Fear Of Missing Out — chasing price up after a strong move because you don't want to be left behind. FUD = Fear, Uncertainty and Doubt — narrative that drives people to sell. Both are emotion-driven and almost always end badly for retail traders.
Fork (hard / soft) Protocol #: A change to the Bitcoin protocol. Soft fork: backwards-compatible — old nodes still accept new blocks (SegWit, Taproot were soft forks). Hard fork: not backwards-compatible — splits the network into two chains (Bitcoin Cash in 2017 was a hard fork).
Full node Protocol #: A computer running Bitcoin Core (or compatible software) that validates and stores the entire blockchain. Anyone can run one. Full nodes are what actually enforce Bitcoin's rules — miners only propose blocks; nodes accept or reject them.

G

Genesis block Protocol #: The first-ever block in the Bitcoin chain — block 0, mined by Satoshi Nakamoto on January 3, 2009. Reward of 50 BTC, but uniquely unspendable (Satoshi never made it part of the UTXO set). Carries the embedded headline message about the bank bailouts.
Golden cross / Death cross TA #: Golden cross: short-term moving average crosses above a long-term one (classically EMA 50 above EMA 200) — bullish trend signal. Death cross: the opposite — bearish trend signal. Both lag — they confirm a move that already started — but as regime markers they're well-watched.

H

Halving Protocol #: Every 210,000 blocks the BTC block subsidy is cut in half. Past halvings: 2012 (50 → 25), 2016 (25 → 12.5), 2020 (12.5 → 6.25), 2024 (6.25 → 3.125). Next: ~spring 2028. Live countdown →
Hardware wallet Wallet #: A dedicated physical device that stores your private keys offline and signs transactions internally — the keys never leave the device. Ledger, Trezor, Coldcard, BitBox are the major brands. Standard recommendation for any meaningful BTC stack.
Hashrate Protocol #: The total computational power miners are throwing at finding the next block, measured in hashes per second. Bitcoin's hashrate is currently in the exahashes (10^18) range. Higher hashrate = harder to attack the network.
HODL Slang #: Holding BTC long-term without selling. Originated as a 2013 Bitcointalk forum typo ("I AM HODLING") that became a meme, then a strategy, then a culture. Now also retconned as "Hold On for Dear Life". The opposite of trying to time the market.

I

ICO Trading #: Initial Coin Offering — selling tokens to fund a project, usually pre-product. Massive 2017 / 2018 mania, mostly faded after regulatory crackdowns. Has been largely replaced by airdrops, IDOs and direct exchange listings.

K

KYC Trading #: Know-Your-Customer — the identity verification process exchanges run before letting you trade or withdraw beyond small amounts. Driven by AML (anti-money-laundering) regulation. Trade-off: required for fiat on / off-ramps; gives up privacy.

L

Lightning Network Protocol #: A layer-2 payment network built on top of Bitcoin. Lets you send near-instant, low-fee transactions by opening "payment channels" with peers and settling final balances on-chain. Currently used by exchanges, some merchants and the Strike app, among others.
Lump-sum buying Trading #: Buying your entire intended position in one transaction, rather than spreading it via DCA. Historically beats DCA in pure return terms when the asset trends up, but has worse drawdown profile if you happen to buy near a cycle top.

M

MACD TA #: Moving Average Convergence Divergence — a trend-following momentum indicator. The MACD line is EMA(12) − EMA(26), the signal line is EMA(9) of the MACD line, and the histogram is the gap between them. Full explainer →
Market cap Trading #: Circulating supply × current price. The headline "Bitcoin is worth $X trillion" number — useful as a rough comparison tool, but criticised because it implies you could realise that valuation by selling everything (you can't; you'd crash the price).
Mempool Protocol #: The pool of unconfirmed transactions waiting to be included in a block. Each node has its own mempool; mempool.space aggregates a popular reference view. A larger mempool = more congestion = higher recommended fees. Full explainer →
Miner / Mining Protocol #: Specialised hardware (ASICs) racing to solve the proof-of-work puzzle for each new block. Winner gets the block reward + fees. Mining secures the network by making history-rewriting prohibitively expensive in electricity costs.
Moon / Mooning Slang #: "To the moon" — a rapid price rally. Used both seriously and ironically. Conjugates: mooning, mooned, moonshot.
MVRV ratio / Z-Score On-chain #: Market Cap / Realized Cap. MVRV above ~3 historically marks overheated tops; below ~1 marks deep value zones. The Z-Score variant normalises MVRV by its historical standard deviation. One of the most-cited on-chain metrics; component of CBBI.

N

Nakamoto consensus Protocol #: The combination of proof-of-work + longest-chain rule that lets Bitcoin nodes agree on a single transaction history without any central coordinator. The original innovation in Satoshi's 2008 white paper.
Node Protocol #: Any computer that participates in the Bitcoin network. Full nodes validate every block and transaction against consensus rules. Light clients (SPV wallets) verify only block headers.
NVT ratio On-chain #: Network Value to Transactions — market cap divided by daily on-chain transaction volume. A "P/E ratio for Bitcoin". High NVT = price elevated relative to network usage. Less reliable since the rise of Lightning (off-chain volume isn't counted) and exchange consolidation.

O

OHLC TA #: Open, High, Low, Close — the four prices that define each candle / bar on a price chart. The four together describe a period's full price action; modern charts usually add volume as a fifth element.
On-chain analysis On-chain #: Reading market signals from data publicly available on the blockchain — UTXO age, exchange inflows / outflows, miner reserves, address activity, transaction counts. Glassnode, CryptoQuant and CoinMetrics are the main commercial providers. Free aggregates available via mempool.space and bitcoin-data.com.
Order book Trading #: The list of standing buy and sell orders on an exchange at each price level. Sometimes called "depth". Thin order books = small trades move price a lot; thick books = liquidity, harder to move.
Oversold / Overbought TA #: Conventionally RSI below 30 = oversold; above 70 = overbought. In real BTC trends these zones can persist for weeks — the textbook "sell at 70 / buy at 30" rule is a frequent source of bad trades. Most useful in ranging markets, not trending ones.

P

P2P Protocol #: Peer-to-peer — direct communication between nodes without a central server. Bitcoin's network is P2P at the protocol level. Also describes P2P trading marketplaces (LocalBitcoins, Bisq, Hodl Hodl) where buyers and sellers meet directly.
Paper hands Slang #: A trader who sells at the first sign of trouble. Counterpart to diamond hands. Pejorative — the implication is that strong hands hold through volatility.
Private key Wallet #: The secret number that lets you spend BTC from a given address. Holding the private key = controlling the coins. Lose it and the coins are gone forever; leak it and anyone can spend. Usually backed up as a 12 or 24-word seed phrase.
Proof of Work (PoW) Protocol #: The consensus mechanism Bitcoin uses to validate new blocks. Miners compete to find a hash below the target difficulty, which requires real electricity and specialised hardware. PoW makes rewriting history expensive — that cost is the security.
Public key Wallet #: Derived mathematically from the private key. Can be shared freely; used to verify signatures and generate addresses. The pair (public / private) is the basis of all Bitcoin signing.
Puell Multiple On-chain #: Daily coin issuance value in USD divided by its 365-day moving average. High Puell = miners are earning unusually well, price likely overheated. Low Puell = miner capitulation, often a cycle bottom. Component of CBBI.

R

Realized cap On-chain #: The total value of all BTC priced at the time each coin last moved on-chain, rather than at the current spot price. A measure of aggregate cost basis. Used to compute MVRV.
Resistance TA #: A price level where sellers have historically stepped in and stopped further upside. The opposite of support. Broken resistance often flips to act as new support on a retest.
ROI Trading #: Return On Investment — (current value − initial cost) / initial cost. Quoted as a percentage. A 100% ROI means your investment doubled.
RSI TA #: Relative Strength Index — a 0–100 momentum oscillator measuring lopsided buying vs selling pressure over the last N candles (default 14). The 30/70 thresholds mark conventional oversold / overbought zones. Full explainer →

S

Satoshi (unit) Protocol #: The smallest Bitcoin unit: 1 BTC = 100,000,000 satoshis ("sats"). Named after the protocol's creator. Often abbreviated "sat" in fee discussions (sat/vB) and pricing.
Satoshi Nakamoto Protocol #: The pseudonymous creator of Bitcoin. Published the white paper on October 31, 2008, mined the genesis block on January 3, 2009, and disappeared from the project in 2011. Identity unknown despite 15+ years of speculation.
sat/vB Protocol #: Satoshis per virtual byte — the fee rate unit for a Bitcoin transaction. Wallets let you set sat/vB (or pick a preset like "fast / medium / slow"). Higher = miners more eager to include your tx in the next block.
SegWit Protocol #: Segregated Witness — a 2017 soft fork that moved transaction-signature data out of the main block area, effectively increasing capacity and fixing transaction-malleability bugs. Addresses starting with bc1q are SegWit.
Seed phrase Wallet #: A 12 or 24-word backup of your private key, drawn from a standardised 2048-word list (BIP-39). Anyone who has your seed has your coins — store offline, never type into a website, never photograph.
Stochastic RSI TA #: An oscillator applied to RSI rather than directly to price. Reacts faster than plain RSI, more useful for short-term overbought / oversold reads, more prone to noise on small timeframes.
Stop-loss Trading #: An automatic exit order placed below your entry to cap downside. Conventional wisdom: every trade should have one. Common mistake: putting it too tight inside normal volatility, getting "stopped out" before the original thesis plays out.
Support TA #: A price level where buyers have historically stepped in and stopped further downside. Opposite of resistance. Broken support often flips to act as new resistance on retest.

T

Taproot Protocol #: A November 2021 soft fork that introduced Schnorr signatures and improved privacy / efficiency for complex Bitcoin transactions. Addresses starting with bc1p are Taproot. Foundation layer for newer protocols like Ordinals and Runes.
Technical analysis (TA) TA #: Reading price charts, indicators (RSI, MACD, EMA, Bollinger Bands) and patterns to forecast where price might go next. Probabilistic, not deterministic — works best combined with fundamentals (on-chain) and risk management.
Timeframe (TF) TA #: The duration each candle / bar on a chart represents. Common Bitcoin timeframes: 1H, 4H, 1D, 1W, 1M. Same indicator on different timeframes can read very differently — higher TFs filter noise but lag.
Transaction (tx) Protocol #: A signed message that moves BTC between addresses. Made up of inputs (which UTXOs are being spent) and outputs (where the BTC is going). Once mined into a block, irreversible.
Trend TA #: The dominant direction of price over a chosen horizon. Uptrend = higher highs + higher lows; downtrend = lower highs + lower lows; sideways = neither. The classic trader rule: "the trend is your friend" — fade it only with strong reason.

U

UTXO Protocol #: Unspent Transaction Output — the data structure Bitcoin uses to represent ownership. Your "balance" is really the sum of all UTXOs you can spend with your private keys. When you send BTC, the inputs (UTXOs being spent) are consumed and new outputs are created.

V

Volume TA #: The amount of BTC (or its USD value) traded over a period. Higher volume = more participation, more reliable price moves. "Low-volume rally" is a common warning — price up but with few buyers backing it is fragile.

W

Wallet Wallet #: Software / hardware that manages your private keys and lets you send / receive BTC. The keys ARE the wallet — the device is just a key manager. Categories: hot (online, e.g. mobile, desktop, web), cold (offline, e.g. hardware wallet, paper backup).
Whale Slang #: An entity holding enough BTC to move markets — typically 1,000+ BTC. Whale wallet movements onto exchanges are watched as potential sell pressure; movements off exchanges as accumulation. Trackable via on-chain analysis.
Whitepaper Protocol #: The 9-page document "Bitcoin: A Peer-to-Peer Electronic Cash System" published by Satoshi Nakamoto on October 31, 2008, describing how Bitcoin works. Still hosted at bitcoin.org/bitcoin.pdf and arguably the most influential 9 pages of computer science of the 21st century.

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