01 /
A–C
- Address
- The string you share to receive crypto, derived from your public key: many Bitcoin wallets use addresses starting with bc1, Ethereum uses 0x. Showing it is safe, but check the whole thing before sending, because a confirmed transaction can't be undone.
- Address poisoning
- A scammer sends you a tiny transaction from an address that looks almost identical to one you use, hoping you'll copy it from your history. A 2025 study counted 270 million attempts over two years on Ethereum and BNB Smart Chain. Check every character.
- Airdrop
- A free distribution of tokens to many addresses, usually to promote a new project or reward early users. Be careful: airdrop tokens that simply show up in your wallet and send you to a website to claim them are a classic phishing lure.
- All-time high (ATH)
- The highest price an asset has ever printed. As of October 2026, Bitcoin's is still the one from October 6, 2025: $126,272 on Bitstamp. Buying right at an ATH out of FOMO is an expensive classic.
- Altcoin
- Any cryptocurrency that isn't Bitcoin: Ethereum, Solana, XRP and thousands more. Some have a real business behind them; others are hype with a logo. My rankings, worst coins included, are in best cryptos.
- Altseason
- A stretch when most altcoins outperform Bitcoin. Blockchaincenter's index only calls it when 75% of the top 50 coins, stablecoins excluded, beat BTC over 90 days. Anything less is wishful thinking.
- Bear market
- A long period of falling prices and pessimism. In stocks the usual line is a 20% drop from the highs; crypto blows past that. Bitcoin fell 77.6% between November 2021 and November 2022.
- Bitcoin (BTC)
- The first cryptocurrency, described by Satoshi Nakamoto in October 2008 and running since January 3, 2009, with a cap of 21 million coins. Start from zero with the what is Bitcoin guide.
- Bitcoin dominance (BTC.D)
- Bitcoin's share of the total crypto market cap. TradingView calculates it over the 125 largest coins, so every site shows a different number. If it drops while altcoins rise, that's the first hint of an altseason. I track it in many Bitcoin analysis videos.
- Blockchain
- A ledger shared by thousands of computers, where transactions are grouped into blocks chained together with cryptography. Changing an old block would mean redoing every block after it, which makes tampering very hard. Bitcoin adds a block every ten minutes on average.
Chapters (6)
- Bull market
- A phase of sustained gains, higher highs and widespread optimism. In crypto it tends to end in euphoria, right when the most people are buying high. Without an exit plan written in advance, everything you gain on the way up can go back on the way down.
- Candlesticks
- A way of charting price where each candle shows the open, close, high and low: green if it closed above where it opened, red if below. They're credited to the rice merchant Munehisa Homma, though even that is disputed.
- CASP
- Crypto-asset service provider: a company authorized under MiCA to hold, exchange or sell crypto in the EU. If you live in Spain, since July 1, 2026 only providers authorized by the CNMV (Spain's market regulator) or another EU regulator may operate there. The exchanges section covers the ones you can use from Spain.
- Cold wallet
- A wallet that keeps your keys offline, usually a physical device that signs transactions internally. Buy it only from the manufacturer's website, never secondhand or from resellers: in October 2026, Ledger devices with a spy implant sold by an Asian reseller turned up. The full comparison is in the hot vs cold wallet guide, and my pick of models in best cold wallets.
- Crypto-asset
- The EU's legal term. MiCA defines it as a digital representation of a value or a right that can be transferred and stored electronically using distributed ledger or similar technology. Bitcoin, stablecoins and nearly all tokens fit.
- Crypto-to-crypto swap
- Trading one coin for another, say BTC for ETH. If you're a Spanish taxpayer, Hacienda (the Spanish tax agency) treats it as a disposal that creates a capital gain or loss even if no euros changed hands, reportable that year.
02 /
D–H
- DAC8
- An EU tax-cooperation directive that applies from January 1, 2026: crypto-asset service providers must report their customers' transactions to tax authorities. What you do on a European exchange leaves a trail. More in crypto taxes in Spain.
- DCA (dollar-cost averaging)
- Investing the same amount at regular intervals, whatever the price does, so you buy more when it's cheap and less when it's expensive. Benjamin Graham coined the term in 1949. Step by step in the Bitcoin DCA guide.
- DeFi
- Decentralized finance: lending, borrowing or swapping through smart contracts, with no bank or exchange in the middle. Services run in a fully decentralized way fall outside MiCA, so if a contract breaks or you slip up, there's no regulator to complain to.
- DEX
- Decentralized exchange: you swap tokens straight from your own wallet against a smart contract, with no account or middleman. Your funds never pass through anyone, but the mistakes are yours too: fake tokens, risky approvals or a worse price from slippage.
- Divergence
- When price and an indicator like the RSI tell different stories. Bearish: price makes a higher high while the RSI makes a lower high. Bullish: price makes a lower low while the RSI makes a higher low. It warns; it doesn't confirm.
- Double top and double bottom
- Two similar highs (or lows) separated by a move the other way. The pattern is only confirmed when price closes beyond that middle point, the neckline; until then it's a pretty drawing, not a signal.
- DYOR
- Do your own research. It's the line that sits under many of my videos, next to “this is NOT financial advice,” and it means reading the white paper, knowing who's behind a project and understanding the risk before you buy, not after.
- Entropy
- The randomness your seed phrase is born from. If it's weak, the seed can be guessed: in July 2026 a firmware bug left some Coldcard seeds with about 72 bits instead of 128, and attackers drained more than 1,800 BTC.
- ETF
- A fund that trades on a stock exchange like a share. In the US, the SEC approved the first spot bitcoin products in January 2024 while stressing it was not endorsing bitcoin. You get price exposure, but the keys aren't yours.
- Ethereum (ETH)
- A blockchain built to run smart contracts; its coin is ether (ETH). Since September 15, 2022 it has run on proof of stake, a switch known as The Merge that, according to ethereum.org, cut its energy use by about 99.95%.
- Exchange
- A platform where you buy and sell crypto for euros or other coins. Leave your balance there and the platform holds the keys, not you. In the EU it must be authorized as a CASP; to check, see exchanges and MiCA.
- Fear & Greed Index
- A 0 (extreme fear) to 100 (extreme greed) gauge that blends volatility, volume, social media, dominance and Google searches. It hit 5, matching its all-time low, in February 2026. Its makers suggest extreme fear can be a buying opportunity.
- FIFO
- First in, first out: the method Spain's tax agency uses for crypto. When you sell only part of your coins, you're deemed to sell the oldest ones first, and their purchase price sets your gain or loss. It can change your bill a lot.
- FOMO
- Fear of missing out: the dread of sitting on the sidelines while others make money. It's what makes you buy after a huge green candle, usually too late. As I put it in one of my video descriptions: don't let FOMO cloud your strategy.
- FUD
- Fear, uncertainty and doubt: negative news or rumors, sometimes true and sometimes made up, that push people into panic selling. Before you react, find the original source and ask yourself who wins if you sell.
- Gas
- The fee you pay on Ethereum for every operation, always in ETH. It's quoted in gwei (1 ETH equals one billion gwei) and climbs when the network is congested. Cutting it is one of the main reasons layer 2 networks exist.
- Golden cross and death cross
- Moving-average signals. A golden cross is when the 50-day average crosses above the 200-day; a death cross is when it crosses below. They sound dramatic, but they arrive late because they're built from past prices.
- Halving
- Bitcoin's mining reward is cut in half every 210,000 blocks, roughly four years. The last halving, on April 20, 2024, brought it to 3.125 BTC; the next is expected around April 2028. More in cycles and halving.
Chapters (6)
- Head and shoulders
- A reversal pattern with three peaks, the middle one highest; in my video titles it's HCH. It's confirmed when price loses the neckline, and the classic target projects the head-to-neckline distance. The inverse version shows up at bottoms and points to a bullish reversal.
- HODL
- Holding your coins no matter what. It started as a typo of “hold” in a forum post on December 18, 2013; the “Hold On for Dear Life” backronym came later. It works better with a plan than with faith.
- Hot wallet
- A wallet connected to the internet: phone apps or browser extensions like MetaMask. It's handy for daily use and for DeFi, but more exposed to malware and phishing. Keep in it only what you could afford to lose.
03 /
I–M
- KYC
- Know your customer: the identity check (ID document, selfie, sometimes proof of address) that any regulated platform requires. It isn't a whim; anti-money-laundering rules demand it. Be wary of anyone who lets you invest without asking for anything.
- Layer 2
- A network built on top of another blockchain, usually Ethereum, that processes transactions off it while inheriting its security. Arbitrum and Base are examples, and ethereum.org presents them as the way to scale with lower fees.
- Leverage
- Trading with borrowed money to open a position bigger than your balance. At 10x, a move of roughly 10% against you can wipe out your margin. If you live in Spain, the CNMV caps crypto CFDs for retail clients at 2:1.
- Liquidation
- The forced closing of a leveraged position once your collateral no longer covers the losses: the margin on that trade is gone. On October 10, 2025, more than $19 billion of leveraged crypto positions were liquidated in roughly a day.
- Liquidity
- How easily you can buy or sell without moving the price. Bitcoin has plenty; a small coin can have so little that your own sale sinks it. EU regulators warn you may not get out when you want, or at the price you expect.
- Long and short
- Going long is betting the price rises; going short, that it falls. In crypto, shorting almost always means leveraged derivatives, so a sharp rally can liquidate you even if you'd have been right in the end.
- MACD
- An indicator from Gerald Appel, dating to the late 1970s: it subtracts two exponential averages, usually 12 and 26 periods, and compares the result with its own 9-period average. It shows shifts in momentum, but it lags and gives false signals in sideways ranges.
- Market and limit orders
- A market order fills instantly at the best available price, even if that's worse than what you saw (slippage). A limit order only fills at your price or better, at the cost of possibly never filling.
- Market capitalization (market cap)
- Price times the number of coins in circulation; it's how you compare sizes. At its October 2025 peak, Bitcoin's was around $2.5 trillion. Also check the fully diluted valuation (FDV), which counts coins that haven't been released yet.
- Memecoin
- A cryptocurrency born from a meme. The first was Dogecoin, created in December 2013 to poke fun at crypto speculation. Its price lives on attention, which leaves as fast as it arrives. Dogecoin and Shiba Inu both get a video in Entiende Cripto.
- MiCA
- The EU's Markets in Crypto-Assets Regulation (EU 2023/1114), fully applicable since December 30, 2024. It requires providers to be licensed and to keep your crypto separate from their own assets. In Spain, the transitional period ended on July 1, 2026. What changed for you is in the MiCA regulation guide.
Chapters (6)
- Mining
- The process in which miners spend electricity and computing power (proof of work) to add blocks to Bitcoin. Whoever finds a block collects the reward, now 3.125 BTC, plus fees. Difficulty readjusts every 2,016 blocks.
- Moving averages
- The average price over the last N periods, recalculated with every candle. The simple one (SMA) weights all data equally; the exponential one (EMA) favors recent prices. The 50-day and 200-day are the most watched for reading the trend.
- Multisig
- A wallet that needs several signatures to move funds, for example two of three keys kept in different places. Lose one or have it stolen and the money is still safe. More security, more complexity: a bad setup can lock you out.
04 /
N–R
- NFT
- Non-fungible token: a unique digital asset that can't be swapped one-for-one the way one bitcoin can for another. Used for art, collectibles or tickets. MiCA leaves out unique, non-fungible crypto-assets, so its protections don't cover you.
- Oracle
- A service that brings outside data, such as prices or results, onto a blockchain, because a smart contract can't look it up on its own. Chainlink is the best known; my Entiende Cripto EP.06 explains the oracle problem in plain terms.
- Perpetual futures
- Leveraged contracts that never expire. To keep them close to the spot price, longs and shorts periodically pay each other a funding rate. Hyperliquid, which I cover in my HYPE video, runs its perpetuals order book fully on-chain.
- Phishing
- A con to steal your keys or logins by posing as someone you trust: an exchange, your wallet, the tax office. In April 2026 a fake Ledger app on Apple's Mac App Store took about $9.5 million. More cases in crypto scams.
- Pig butchering
- Someone builds your trust over social media or dating apps, then steers you to a fake platform showing made-up profits. When you try to withdraw, “taxes” appear. The FBI counted $7.23 billion lost to crypto investment fraud in 2025.
- Private key
- The secret number that signs your transactions and proves the coins are yours: whoever holds it is in charge. EU regulators put it bluntly: losing your private keys means permanently and irreversibly losing access and ownership.
- Proof of stake (PoS)
- A consensus system where validators lock up coins as collateral instead of burning electricity. Cheat and you lose part of the stake (slashing). Ethereum has used it since September 2022, and running your own validator takes 32 ETH.
- Proof of work (PoW)
- Bitcoin's consensus system: to add a block, you must find, by sheer computation, a hash that meets a very hard condition. The white paper sums it up as “one-CPU-one-vote.” Rewriting history would mean redoing all that work.
- RSI
- The relative strength index, created by J. Welles Wilder in 1978: it swings between 0 and 100, usually over 14 periods. Above 70 is called overbought and below 30 oversold, though in strong trends it can stay there for a long time.
- Rug pull
- The people behind a project vanish with the money, pulling the liquidity or dumping their tokens all at once. It's common with freshly launched tokens, anonymous teams and return promises that don't add up.
- RWA and tokenization
- Real-world assets, such as US Treasuries, gold or real estate, represented as tokens on a blockchain. They let you split up and trade around the clock things that used to be hard to buy, but they depend on a serious issuer and real custody.
05 /
S
- Satoshi
- The smallest unit of bitcoin: one hundred-millionth, or 0.00000001 BTC. It's named after Satoshi Nakamoto, the pseudonym behind Bitcoin. You don't need to buy a whole bitcoin; a few euros' worth of sats is fine.
- Scalping
- Ultra-short-term trading: lots of trades lasting minutes, chasing small moves. It takes discipline, low fees and a stop-loss that's always on. My trading videos include a beginner strategy, but the research is harsh: most day traders lose money.
- Seed phrase (BIP-39)
- A list of 12 to 24 words, drawn from a 2,048-word dictionary, that generates every key in your wallet under the BIP-39 standard. Anyone who sees it can empty your wallet. Keep it on paper or metal, never in photos, the cloud or websites.
- Self-custody
- Holding the keys to your crypto yourself, in your own wallet, with no exchange in between. If a platform goes bust, as FTX did in November 2022, your coins aren't there. The flip side: lose your seed phrase and nobody can recover it. How to do it right is in the security section.
- Smart contract
- A program stored on a blockchain that runs by itself when its conditions are met, in an “if this, then that” style. Nick Szabo, who coined the term, described it in 1994, and ethereum.org compares it to a vending machine.
- Spot market
- Buying and selling the actual coin, delivered immediately, with no leverage or contracts involved. If you buy bitcoin spot and it drops 50%, you lose half, but nobody liquidates you and you can move it to your own wallet.
- Stablecoin
- A cryptocurrency that tries to hold a steady value, almost always pegged to the dollar or the euro. In the EU, those pegged to a single currency need an issuer authorized under MiCA, and as of October 17, 2026, USDT isn't in ESMA's register.
Chapters (7)
- Staking
- Locking up coins on a proof-of-stake network to help validate it in exchange for rewards. On Ethereum, your own validator takes 32 ETH and can be penalized if it fails. Staking through an exchange is easier, but your coins sit in its hands.
- Stop-loss
- An order that closes your position if price reaches the level where your idea stops making sense. It doesn't prevent losses; it limits them. In very sharp drops it can fill worse than planned. How to place one is covered in the risk management guide.
- Support and resistance
- Price zones where buyers (support) or sellers (resistance) showed up before. When resistance breaks with force, it often turns into support. They're zones, not exact lines. All of this, with charts, in the technical analysis guide.
- Swing trading
- Trading moves that last days or weeks, on four-hour or daily charts, rather than minutes. It needs less screen time than scalping and the signals tend to be more reliable; my trading-versus-investing video explains why.
06 /
T–Z
- Take profit
- An order that closes all or part of your position when price hits your profit target. Setting it before you enter protects you from greed, because markets don't rise forever and gains you don't lock in can disappear.
- Timeframe
- The period each candle covers: 15 minutes, 4 hours, a day, a week. The same chart tells different stories depending on which you pick. House rule: the higher the timeframe, the more reliable the signal, and the weekly outranks the five-minute.
- Token
- A digital asset created on top of an existing blockchain, like the thousands of tokens living on Ethereum. It's distinct from each network's native coin (BTC on Bitcoin, ETH on Ethereum). The fact that a token exists doesn't mean it does anything useful.
- Total3
- The market cap of all crypto except Bitcoin and Ethereum, as in TradingView's TOTAL3 index. It's the altcoin thermometer: if it climbs hard while BTC dominance falls, that's a sign money is flowing into altcoins.
- Travel Rule
- An EU regulation (2023/1113) that makes providers pass along sender and recipient details with every crypto transfer between platforms. If you move more than €1,000 to your own wallet, the platform must check that it's really yours.
- Triangle
- A pattern where price gets squeezed between two converging lines. For symmetrical triangles in stocks, Bulkowski measured an upward breakout 60% of the time, on average three-quarters of the way to the apex. Wait for the breakout and watch volume.
- Unlicensed firm (chiringuito)
- What Spain's CNMV informally calls a “chiringuito financiero”: a firm offering investment services without authorization. They promise big returns with no risk, rush you and sometimes use official logos. Before you send a cent, search the CNMV warnings.
- Volatility
- How much and how fast a price moves. In every bear market through 2022, Bitcoin fell more than 75% from its peak, and in 2025–2026 it gave up 54%. If that keeps you up at night, your position is too big.
- Volume
- The amount traded in a period. It confirms or contradicts moves: a breakout on high volume is more believable than one on thin volume. Be careful with data from unreliable exchanges, which can be inflated.
- Wallet
- The app or device that stores your keys, not your coins, which always live on the blockchain. That's why your seed phrase can restore the same wallet on a new device if you lose the original. Hot or cold? The video below compares both.
Chapters (7)
- Wedge
- A pattern where price moves between two converging lines tilted the same way; my titles call it “cuña.” The falling wedge tends to break upward: 68% of the time in Thomas Bulkowski's statistics, which come from stocks, not crypto. The rising wedge breaks down 60% of the time, and Bulkowski ranks it among the worst-performing patterns.
- Weekly close
- The price at which the weekly candle closes, the one that carries the most weight in my analyses. Crypto trades 24/7, so the cutoff depends on the platform: Binance uses Monday 00:00 UTC; Kraken's data groups weeks Thursday to Thursday.
- Whale
- A person or entity holding so much of a coin that their buying and selling can move the price, especially in small coins. Their moves show up on the blockchain, but a big transfer isn't always a sale.
- White paper
- The document where a project explains what it does and how it works. Bitcoin's runs nine pages. Under MiCA one is mandatory to offer crypto-assets to the public in the EU, no regulator approves it, and it can't promise the token's future value.