Bitcoin: Digital Gold Explained
7 key takeaways
- Bitcoin launched in January 2009; its creator, Satoshi Nakamoto, is anonymous and inactive.
- Supply is capped at 21 million coins; about 94% have already been mined.
- Every ~4 years the block reward halves (the 2024 halving cut it to 3.125 BTC).
- Miners secure the network with electricity and are paid in new coins plus fees.
- Spot Bitcoin ETFs (approved in the US in January 2024) let traditional accounts hold exposure.
- BTC is volatile: 50–80% drawdowns have happened in every cycle.
- The investment thesis is scarcity plus the strongest security of any network.
Why 21 million
Bitcoin's issuance schedule is written into the code and enforced by every node. New coins enter only as block rewards, and those rewards halve on a fixed schedule until roughly the year 2140. No central bank can print more; changing the cap would require convincing the whole network to run new rules — something no group has ever achieved.
Mining in one paragraph
Miners race to find a number that makes the block hash fall below a target. The winner broadcasts the block and collects the reward. Difficulty adjusts every 2,016 blocks so blocks arrive about every 10 minutes no matter how many miners join. The energy spent is the cost of attacking the network: to rewrite history you would need more computing power than every honest miner combined.
The halving cycle
Rewards: 50 BTC (2009) → 25 (2012) → 12.5 (2016) → 6.25 (2020) → 3.125 (2024) → 1.5625 (expected 2028). Historically, the 12–18 months after each halving saw strong price appreciation as new supply shrank, though the sample size is small and past cycles are not a guarantee.
Get the 7-in-7 Digest
Seven stories, seven minutes, every week. Plus the free 7-Step Starter Kit PDF.
How people hold BTC
Four routes: an exchange account (easiest, custodial — see our Top 7 Exchanges), a self-custody wallet (you hold the keys — Top 7 Wallets), a spot ETF in a brokerage account (no keys, standard tax treatment), or a Bitcoin treasury company's stock (indirect, leveraged). Most long-term holders use a hardware wallet for the bulk and an exchange for buying.
Risks worth naming
Volatility, regulatory shifts, loss of keys, exchange failures (Mt. Gox 2014, FTX 2022), and the possibility that mining revenue from fees alone fails to secure the network decades from now. None of these are hidden; price them in.
Watch
But how does Bitcoin actually work? — 3Blue1Brown
What is Bitcoin? (v2) — WeUseCoins
Frequently asked questions
Can I buy less than one Bitcoin?
Yes. One BTC divides into 100 million satoshis; you can buy $10 worth on any exchange.
Is Bitcoin legal?
Legal to own in most countries; a few restrict or ban it. Check local rules before buying.
ETF or self-custody?
ETF for simplicity inside retirement accounts; self-custody if you want to actually own the asset and transact with it.