Anyone can copy the code

Wonder

1. Why does a perfect copy of Bitcoin’s source code start with zero value?
2. What distinguishes a fork that inherits balances from one that starts empty?
3. How much hash power does it take to attack a chain that shares an algorithm but not the community?

Explore

1. Bitcoin Core is released under the MIT license, a permissive open-source standard. Since January 2009, anyone has been free to download the C++ source, modify parameters, and compile a new binary. The technical barrier to entry is negligible; thousands of forks have emerged over the years, each technically valid but economically distinct. This openness was deliberate, ensuring no single entity could control development or distribution of the software itself.
2. A fork inherits none of Bitcoin’s accumulated assets. It lacks the existing ledger with its holders, the established miner hashrate, the node operators maintaining consensus, and the liquidity on exchanges. It also lacks seventeen years of continuous uptime and a developer community with institutional memory. A copy starts from zero network effects. The code is merely the instruction set; the value resides in the agreement among participants to run it.
3. Security scales with economic participation. A small chain using SHA-256 proof-of-work is vulnerable to attack by a fraction of Bitcoin’s hashrate. An attacker can rent mining power to double-spend transactions or reverse blocks because the cost to secure the chain is low relative to its market capitalization. This exposes a critical trade-off: while the algorithm provides cryptographic integrity, economic inertia provides security against coercion and reversal.
4. Early forks like Namecoin (2011) and Litecoin (2011) modified parameters but started with empty ledgers. They required new communities to adopt them from scratch. In contrast, Bitcoin Cash (2017) and Bitcoin SV (2018) were hard forks of the existing ledger. Holders of BTC at the August 2017 fork received an equal amount of Bitcoin Cash (BCH), and BCH holders at the November 2018 split received Bitcoin SV. These chains inherited balances but fractured the network, as node operators and miners chose which chain to support.
5. The block-size war (lesson 3.3.5) showed that consensus is about people, not code. Large miners and companies backed bigger blocks through the SegWit2x agreement; node operators and users refused to run it, SegWit2x was called off in November 2017, and those who wanted bigger blocks left with Bitcoin Cash. Hashrate and corporate agreement could not force a rule change that node operators would not adopt.
6. To verify this dynamic, open a block explorer and compare the total market capitalization of Bitcoin against any active altcoin fork. Note the disparity in liquidity depth. Then check the hashrate charts for both chains over the last thirty days. The ratio reveals how much economic effort each network dedicates to security. This gap explains why clones remain speculative instruments rather than serious monetary competitors.

Key facts

Exercise nine, six, three, one

Fact check

Dates, figures and claims checked against the published sources listed below.

• Bitcoin Core, 'MIT License' (github.com/bitcoin/bitcoin/blob/master/COPYING)
• J. Bier, The Blocksize War (2021)