Seven battle cries.
One ₿itcoin.

Bitcoin has no CEO, no headquarters and no off switch. Its strength comes from the number of independent people who run it: miners spending real electricity, node operators checking every rule, and holders who refuse to accept a changed version.

Money is a network good. A currency is only as useful as the number of people who will take it, and each new participant makes it more useful for everyone already there. Lyn Alden's Broken Money tells the history of money through exactly this lens: money follows the best available settlement network.

Where the strength comes from

• Miners secure the ledger with proof-of-work, an idea that traces back to Adam Back's Hashcash (1997), cited in the Bitcoin whitepaper.
• Pools let small miners combine forces. The first one, launched in 2010 by Marek "Slush" Palatinus from Prague, was literally strength in numbers.
• Nodes are the referees. Thousands of them, run by ordinary people, reject any block that breaks the rules.
• People teach each other. Meetups and conferences such as BTC Prague are how the network grows in this part of the world.

A bank asks you to trust its statement. Bitcoin lets you check. A full node downloads every block since 2009 and verifies every signature, every amount and every rule on its own computer. If anyone, even a big miner or exchange, tries to break a rule, your node simply ignores them.

This is why the 21 million limit is real. It isn't a promise from a company; it is a rule thousands of independent nodes enforce. Jameson Lopp regularly tests how long it takes to sync a full node on cheap hardware, because the cheaper verification stays, the more people can do it.

How to start

• Download Bitcoin Core and verify the file's signature before running it. Yes, you verify the verifier.
• A plug-and-play node box (Raspberry Pi class hardware, about 1–2 TB SSD) also works.
• Point your wallet at your own node, so it stops asking a stranger's server about your balance.

On the blockchain, nobody "has an account". Coins sit at addresses, and whoever controls the private key can move them. If an exchange holds the key, you own an IOU from the exchange. That IOU disappears when the exchange freezes withdrawals, gets hacked or goes bankrupt.

History keeps teaching this: Mt. Gox (2014), Celsius and FTX (2022). Each time, customers who had withdrawn to their own wallets lost nothing.

Your seed phrase in plain words

• Your wallet's keys come from 12 or 24 words (the BIP39 standard, co-authored by Pavol Rusnák and Marek Palatinus of Trezor).
• Write them on paper or steel. Never photograph them, never type them into a website, never share them with "support".
• Start small: move a test amount, restore the wallet from the words, then move the rest.

The word was born on 18 December 2013, when a forum user titled a slightly drunk post "I AM HODLING" while the price crashed. The typo stuck, because the idea behind it is serious: most people lose money in Bitcoin not by buying, but by selling in panic at the bottom.

Saifedean Ammous calls this low time preference: valuing the future over the present. Hard money rewards patience. Every four-year cycle so far has come with a brutal crash, and every crash so far has later been exceeded by a new high.

A HODL plan that survives a crash

• Only hold what you won't need for at least four years, a full halving cycle.
• Decide before the crash what you'll do during it. Write it down.
• Keep coins in self-custody, so selling takes effort rather than one tap.
• Keep an emergency fund in normal money, so life never forces you to sell.

You don't need a whole bitcoin. One bitcoin splits into 100,000,000 satoshis (sats), so ten euros buys a real, spendable piece of it. Thinking in sats removes the "it's too expensive" excuse.

Stacking sats means buying a fixed amount on a fixed schedule, every week or month, whatever the price. This is dollar-cost averaging (DCA). You stop trying to time the market, and you automatically buy more sats when the price is low.

Do it well

• Use a bitcoin-only service with recurring buys, low fees and automatic withdrawal to your own wallet.
• Withdraw in batches, not after every buy, to keep network fees small.
• Pick an amount you won't notice missing, then forget about it.
• Skip anything that offers "yield" on your bitcoin. See module 03.

A bank transfer needs permission at every step: your bank, the receiving bank, a correspondent bank, compliance desks, opening hours. Any of them can delay or block it. A bitcoin transaction needs a valid signature and a fee. That's it. It works on Sunday, across borders and for anyone with a phone.

Nick Szabo put the principle in a 2001 essay: trusted third parties are security holes. Martin learned it first-hand in 2012, when regulators shut down the GoldMoney payment network his gold-paying shop depended on. Bitcoin has no such network to shut down.

The two layers

• On-chain: final settlement, about every 10 minutes. Best for savings and larger amounts.
• Lightning: instant, near-free payments built on top. Best for coffee-sized amounts. Jack Mallers' Strike made it mainstream.

The supply side is pure arithmetic. Every 210,000 blocks (about four years) the new-coin reward halves. It started at 50 BTC per block, fell to 3.125 BTC in April 2024, and will reach zero around 2140. Total supply can never exceed 21 million. No central bank, CEO or miner can print more.

Demand is the human side. Companies such as Michael Saylor's Strategy hold bitcoin as a treasury reserve, spot ETFs opened the door to pension money, and lawmakers like Senator Cynthia Lummis have proposed a national strategic reserve. Meanwhile, as Lawrence Lepard argues in The Big Print, fiat currencies keep expanding.

Fixed supply plus growing demand is the bull thesis. PlanB's stock-to-flow model tried to turn this into price targets.