Lessons
🪙 Crypto
Blockchains, wallets, DeFi. Real crypto literacy, scam-proof.
Free to play. No ads, no token, no account needed to start.
What is a blockchain
Blocks, consensus, and why any of this works without a boss.
- Money before cryptoIn autumn 2008, banks were collapsing and governments spent hundreds of billions bailing them out. On 31…
- Blocks & chainsPicture a notebook where each page lists a batch of transactions: 'Ana sent 0.1 BTC to Ben'. Each new page…
- Consensus: how strangers agreeThousands of computers around the world each hold a copy of the ledger. So who decides which new block is the…
- Nodes, miners & validatorsNo company runs Bitcoin or Ethereum. Thousands of volunteers do, by running free software on ordinary…
- Boss: Blockchain foundationsPublished in the middle of the 2008 banking crisis, it solved the double-spend problem with a public ledger…
Wallets & keys
Keys, seed phrases, and custody: how to truly own your coins.
- Keys, not coinsSurprise: there are no coins inside your crypto wallet. Every coin lives on the blockchain, a shared ledger…
- The seed phraseWhen you create a wallet, it shows you 12 or 24 ordinary words: the seed phrase. Those words mathematically…
- Custodial vs self-custodyBuy crypto on an exchange and the exchange holds the keys. Your "balance" is really an IOU, a promise that…
- Anatomy of a transactionEvery crypto transaction makes the same journey: your private key signs it, your wallet broadcasts it to the…
- Boss: Wallet masteryCoins live on the blockchain; wallets hold keys. The mailbox is on the street; you just carry the key.
Self-custody & security
Scams, approvals, cold storage: become hard to rob.
- The scam bestiaryCrypto scammers stole billions of euros last year, and almost every heist used one of a handful of well-worn…
- Token approvals: the silent drainTo let a swap site trade your tokens, you first sign an 'approval': a permission slip letting that site's…
- Hardware wallets & cold storageA hardware wallet is a small offline device that holds your private keys and never lets them leave. Your…
- Opsec for humansMost people who lose crypto weren't out-hacked; they were out-prepared. Good operational security is a handful…
- Boss: Security gauntletUnsolicited DM, urgency, seed request: three tells in one message. There is no scrambled or partial way to…
The crypto map
BTC, ETH, alts, stablecoins, CEX vs DEX: the whole territory.
- Bitcoin vs EthereumBitcoin and Ethereum top every chart, but they're playing different games. Bitcoin wants to be digital gold…
- Altcoins & the long tailEvery crypto that isn't Bitcoin is an 'altcoin', and there are tens of thousands of them, from Ethereum down…
- Stablecoins: crypto's dollarsStablecoins are tokens built to sit at $1: crypto's cash. Some are backed by real dollars in reserve (USDC…
- CEX vs DEXA centralized exchange (CEX) is a company: it matches buyers and sellers in an order book and holds your coins…
- Boss: Map of the territoryDigital gold versus programmable settlement layer. Judging either one by the other's job is the classic…
Ethereum & the EVM world
A gas-powered world computer, and the standard half of crypto copied.
- The world computerIn 2013, a 19-year-old named Vitalik Buterin asked: why should a blockchain only move coins? What if it could…
- Accounts & gasEthereum has two kinds of accounts. An EOA (externally owned account) is controlled by a person holding a…
- The EVM standardThe EVM (Ethereum Virtual Machine) is the engine that executes smart contracts, and dozens of other chains…
- Token standardsIn 2015 a proposal called ERC-20 defined a common rulebook for tokens on Ethereum: the same functions, the…
- Review: the EVM worldEthereum is a shared computer: EOAs (people with keys) and contract accounts (code) act on it, every action…
The scaling problem
Why block space is scarce, and why 'just make blocks bigger' started a war.
- The blockchain trilemmaEvery blockchain juggles three properties: decentralization (many independent nodes share control), security…
- Block space is scarceIn December 2017, a game called CryptoKitties (collectible digital cats you breed on-chain) went viral and at…
- Why not just bigger blocks?Fees too high? Just make blocks bigger: more space, cheaper transactions. Obvious, right? Bitcoin spent 2015…
- Paths to scaleIf bigger blocks alone won't do it, what will? Three broad paths emerged. One: build a beefier L1 that demands…
- Review: the scaling problemBlock space is scarce, so users bid for it, and when cats or NFTs go viral, fees explode. The obvious fix…
Layer 2s
Rollups: do the work upstairs, settle the bill on Ethereum.
- Rollup intuitionImagine paying a card fee on every single drink at a bar. Absurd. You run a tab and settle once. Rollups apply…
- Optimistic vs ZKHow does Ethereum know a rollup's batch is honest? Two schools. Optimistic rollups (Arbitrum, Optimism) assume…
- Bridging L1 ↔ L2Moving funds INTO a rollup via its official ('canonical') bridge is quick: lock on L1, appear on L2 within…
- L2 economicsOn a busy day, a token swap on Ethereum L1 can cost €10-50 in gas. The same swap on a major rollup often costs…
- Review: Layer 2sRollups execute upstairs and settle on Ethereum, splitting one L1 fee across thousands of users. Optimistic…
The multichain world
Alt-L1s, bridge hacks, and the honest fight over crypto's endgame.
- Alt-L1sWhile Ethereum built layers, other L1s attacked the trilemma head-on. Solana is the poster child: blocks under…
- Bridge riskA multichain world needs bridges, and bridges became crypto's most expensive crime scene. March 2022: the…
- Choosing a chainEvery chain flashes big numbers: users! volume! value locked! The catch is that activity can be rented. Chains…
- The interop futureWhere does the multichain world go? One camp bets on shared security: new chains renting safety from an…
- Boss: Scaling the world computerThousands of machines do the work, gas pays for it, and junk traffic prices itself out. Total fee = gas used ×…
AMMs & DEXes
How a pot of tokens and one formula replaced the order book.
- The pool replaces the order bookA stock exchange matches buyers with sellers in an order book: no seller, no trade. An AMM (automated market…
- x·y=k, minus the fearTake a tiny pool: 10 ETH and €20,000 in stablecoins. Multiply them: 10 × 20,000 = 200,000. That's k, and the…
- Being an LPEvery swap pays a small fee (0.3% on Uniswap's classic pools), and that fee doesn't go to a company. It goes…
- Impermanent lossLPing has an honest cost. When ETH pumps, arbitrageurs buy the pool's cheap ETH until its price catches up, so…
- Unit review: pool smartsAMMs replace order books with a pot of two tokens priced by x·y=k. The token ratio sets the price; every trade…
Lending & borrowing
Loans with no credit check: just collateral, math, and a liquidation bot watching.
- Loans without trustA bank lends you money because it knows your name, your salary, and a court that can chase you. A DeFi…
- Liquidations & cascadesEvery DeFi loan has a health factor: a live score of how far your collateral sits above the liquidation line…
- Why borrow at all?Locking €150 to borrow €100 sounds absurd until you see why people do it. Reason one is leverage: borrow…
- Looping: leverage in a trench coatLooping is DeFi's favorite magic trick: deposit ETH, borrow stablecoins against it, swap them for more ETH…
- Unit review: the lending gauntletDeFi lends to strangers by trusting collateral instead of people: lock €150+, borrow €100. The health factor…
Stablecoins & yield
Every APY has a source: fees, borrowers, or freshly printed tokens.
- Where yield actually comes fromEvery DeFi yield on Earth traces back to exactly three sources. One is trading fees: traders pay to swap in a…
- Staking, farming, 'real yield'Crypto marketing loves three words. 'Staking': locking coins to help secure a proof-of-stake chain, earning…
- veTokenomics & the Curve warsCurve, the giant stablecoin DEX, invented a twist: lock your CRV tokens for up to four years and you get…
- The yield checklistBack in League 1 you learned the mantra: always ask where the yield comes from. That question would have saved…
- Unit review: follow the yieldEvery DeFi yield comes from trading fees, borrow interest, or token emissions. The first two are earned; the…
The DeFi risk stack
Code, oracles, and admin keys: the risks stacked under every APY.
- Smart-contract riskA smart contract does exactly what its code says, including the parts the authors didn't mean. The DAO hack…
- Oracle risk & flash loansA lending protocol can't see the world; it learns prices from an oracle, a data feed. Trick the feed and you…
- Governance & admin keys'Decentralized' is a spectrum, not a badge. Many protocols keep an admin key or a small multisig that can…
- The DYOR checklist'Do your own research' usually means nothing; it's a hashtag people type before aping in. Let's make it a…
- Boss: DeFi graduateRatio in, price out, and every trade tilts the ratio. That's the whole engine of a DEX.
Token design
Supply schedules, emissions, and the fine print that decides who gets paid.
- Where coins come fromEvery token has a monetary policy written in code. Bitcoin caps supply at 21 million, forever. Dogecoin mints…
- The unlock icebergMarket cap = price × the coins actually circulating today. FDV (fully diluted valuation) = price × ALL coins…
- Who gets paidWhen a token launches, the supply gets sliced up before you ever see it: a chunk for the team, a chunk for…
- Cliff divingLocked tokens don't stay locked. A typical deal: a 12-month 'cliff' during which insiders can sell nothing…
- Unit review: token designYou can now read a token's DNA: the supply schedule (fixed, inflationary, or burning), FDV versus market cap…
Reading a token
Allocation pies, ponzinomics, and the checklist that spots exit liquidity.
- The allocation pieAlmost every project publishes a pie chart of who gets the tokens. Bitcoin's pie is boring: 100% mined into…
- What is it for?Ask what a token is FOR and there are three honest answers. Utility: you need it to use the network, like ETH…
- PonzinomicsIn 2022, Terra's Anchor protocol offered a 'stable' 20% yield. The yield wasn't earned; it was paid from a…
- The checklistEverything in this league so far compresses into a five-question checklist you can run in ten minutes: Who…
- Unit review: reading a tokenYou've learned to read the allocation pie, name what a token is for (utility, governance, meme, or nothing)…
NFTs beyond jpegs
Provenance, mania, market tricks, and the uses that might survive.
- What you actually ownAn NFT (non-fungible token) is a unique token on a blockchain. For most NFT art, the chain doesn't store the…
- Mania and bustIn March 2021, Christie's auctioned a digital collage by the artist Beeple for $69 million, and NFT mania went…
- Floors, sweeps and miragesNFT markets have their own vocabulary (floors, sweeps, bids) and their own tricks. The biggest trick is wash…
- Beyond artStrip away the monkey pictures and an NFT is a transferable, publicly verifiable receipt. That's useful in a…
- Unit review: NFTsYou now know what an NFT actually is (a provenance record, not a jpeg), what the mania taught (attention…
DAOs & governance
Token votes, treasury raids, and finding out who really holds the keys.
- Orgs run by tokensA DAO (decentralized autonomous organization) is a group that coordinates money and rules through smart…
- Attacking the voteIn April 2022, the DeFi project Beanstalk was robbed by democracy. An attacker used a flash loan to borrow a…
- Who does the workPeek inside a big 'decentralized' organization and you'll usually find something familiar: a paid core team…
- Who holds the keysBefore trusting any protocol's governance, run a quick power audit: How concentrated are the tokens? What's…
- Boss: Token masterCap = €2 × 200M = €400M; FDV = €2 × 2B = €4B. The €3.6B gap is the iceberg below the waterline.
Staking & restaking
Where staking yield really comes from, and what happens when you stack risk on top of it.
- Where staking yield comes fromIn September 2022, Ethereum switched from miners to stakers (the Merge). Validators now lock up ETH, take…
- Liquid staking tokensSolo staking on Ethereum needs 32 ETH and locks it up. Liquid staking pools fix both: deposit any amount, and…
- Restaking: stacked riskRestaking, popularised by EigenLayer from 2023, lets staked ETH do double duty: the same stake that secures…
- Choosing your staking exposureThere are four main ways to stake: solo (your own validator, 32 ETH, full control), pooled (small amounts…
- Unit review: yield with eyes openStaking yield = issuance + fees, kept honest by slashing. LSTs make stake liquid but add depeg and pool risk…
RWAs & tokenization
Treasuries, buildings, and funds on-chain, and the awkward question of who holds the real thing.
- What tokenization meansTokenization means issuing a blockchain token that represents a real-world asset (RWA): a government bond, a…
- Tokenized treasuriesFor years, on-chain dollars paid nothing while US treasuries paid ~5% (2023). Tokenized treasury funds closed…
- The custody questionEvery RWA token hides the same question: WHO holds the actual bond, building, or gold bar, and what does your…
- TradFi meets DeFiIn January 2024, US spot Bitcoin ETFs launched and gathered tens of billions within a year. BlackRock…
- Unit review: paper, promises, chainsTokenization moves the ledger, not the asset. Tokenized treasuries pass real bond yield to holders, the rare…
AI × crypto
Agents with wallets, decentralized compute, narrative coins, and the deepfakes hunting your keys.
- AI agents with walletsAn AI agent can't open a bank account; banks require a legal person. But a crypto wallet is just a key pair…
- Decentralized compute & dataAI is hungry for compute, and GPUs are scarce and expensive. Decentralized compute networks (like Render or…
- AI-coin diligenceIn every hype wave, hundreds of coins bolt the hot word onto their name. In 2024-25 the word was 'AI'. Some…
- AI-powered scamsScammers now run deepfake video livestreams of famous CEOs promoting 'giveaways', clone voices from seconds of…
- Unit review: signal vs noiseReal: wallets let software pay software, and decentralized compute has a genuine (if narrower-than-advertised)…
Protocol due diligence: capstone
The full framework: vet anything, size it for the frontier, and graduate scam-proof.
- The full DD frameworkEverything you've learned compresses into five lenses: TEAM (who, and are they accountable?), CODE (audited…
- Narrative cyclesCrypto attention moves in waves: ICOs (2017), DeFi summer (2020), NFTs (2021), L2s (2022-23), AI coins…
- Position sizing the frontierFrontier bets (restaking farms, AI coins, brand-new protocols) can go to zero without warning, so you size…
- The graduate's rulesEverything distills to seven rules: 1) Your keys, your coins: guard the seed phrase with your life. 2) Ask…
- Boss: Crypto masterOne public ledger, verified by thousands of computers, made digital scarcity possible without a middleman…