Bitcoin

What is Bitcoin?

Bitcoin (BTC) is the original cryptocurrency, launched in January 2009 by the pseudonymous developer Satoshi Nakamoto. It runs on a proof-of-work blockchain secured by tens of thousands of independent mining nodes and full nodes spread across every continent. The protocol enforces a fixed maximum supply of 21 million coins — a design choice that separates Bitcoin from every fiat currency and from most other digital assets, where supply schedules can be quietly rewritten.

In 2026, Bitcoin sits at the centre of crypto markets as a macro asset. US spot Bitcoin ETFs have absorbed roughly $130 billion in cumulative net inflows since their January 2024 launch and now hold well over one million BTC between them. Similar products trade in Hong Kong, Brazil, the UK, and multiple EU markets. Corporate treasuries — most visibly Strategy (formerly MicroStrategy) with over 500,000 BTC — carry material exposure, and a growing number of sovereign wealth funds and pension funds hold direct BTC through custody providers.

The June 2026 all-time high near $71,360 — followed by a sharp drawdown into $58,000 by month-end — reset expectations about how far the ETF wrapper can carry price without a fresh narrative. Post-halving mechanical bull-market templates from prior cycles have not repeated cleanly this time. What has changed is the structural bid: passive ETF flows now absorb an on-average net-buyer share of daily supply from miners, making sustained bear-market grinds harder to sustain than in 2018 or 2022.

How Bitcoin actually works

Every Bitcoin transaction is broadcast to the peer-to-peer network and grouped into blocks roughly every ten minutes. Miners compete to solve a cryptographic puzzle — SHA-256 double-hashing under a target difficulty — and the first miner to find a valid solution earns the block subsidy plus all transaction fees included in the block. Difficulty automatically retargets every 2,016 blocks (roughly two weeks) to keep block times close to ten minutes regardless of total network hashrate.

The chain with the most accumulated proof-of-work wins by consensus. Reversing a confirmed block would require rebuilding all subsequent blocks with more hashpower than the honest network — a task that becomes exponentially harder as more blocks pile on top. For high-value transfers, six confirmations (roughly one hour) is the industry standard for practical finality.

Bitcoin's censorship resistance comes from client-side verification. Every full node independently checks every rule of the protocol — total supply, signature validity, script correctness, block size, and every historical block since genesis. A single node running on a laptop can reject any block or transaction that violates consensus, no matter how much hashpower stands behind it. This is what makes soft forks (backwards-compatible upgrades like SegWit in 2017 and Taproot in 2021) hard to force through and hard forks (breaking changes) practically impossible to sustain at scale.

Tokenomics and the halving cycle

Bitcoin's monetary policy is simple, transparent, and — most importantly — unchangeable without near-unanimous network consensus. Every 210,000 blocks (approximately four years), the block subsidy halves. The full history:

• 2009-2012: block subsidy 50 BTC per block.
• 2012: first halving to 25 BTC.
• 2016: second halving to 12.5 BTC.
• 2020: third halving to 6.25 BTC.
• April 2024: fourth halving to 3.125 BTC (current subsidy).
• ~April 2028: fifth halving to 1.5625 BTC.
• ~2140: block subsidy asymptotically approaches zero; miners are fully fee-supported.

As of July 2026, roughly 19.85 million BTC of the 21 million cap are in circulation — meaning over 94% of all Bitcoin that will ever exist has already been mined. The remaining 6% will be issued over the next 114 years at a shrinking rate. Practically, Bitcoin's inflation rate in 2026 is approximately 0.83% annually, lower than gold and lower than every major fiat currency's monetary base growth target.

The halving cycle creates a supply-side shock that historically preceded major bull markets 12-18 months after each event. The 2024 halving followed the same rough pattern, though the ETF-driven early rally arrived before the halving rather than after it, compressing the traditional cycle. The 2028 halving will drop miner rewards below 1.6 BTC per block for the first time — a threshold at which fee revenue becomes existentially important for hashrate security.

The Lightning Network and Bitcoin scaling

Bitcoin's base layer processes roughly 5-7 transactions per second — deliberately conservative to keep node operation feasible on modest hardware. Higher throughput happens off-chain, primarily through the Lightning Network: a mesh of bidirectional payment channels anchored by on-chain multisig commitments. Lightning payments settle in milliseconds at fees of fractions of a cent, with final settlement to the base chain happening only when channels open or close.

In 2026, Lightning capacity sits in the range of 5,000-6,000 BTC across roughly 50,000 public channels, with an unknown but larger private-channel footprint. Major exchanges (Kraken, Bitfinex, Binance) offer Lightning withdrawals and deposits, and merchant integration has quietly matured through custodial providers like Strike, Wallet of Satoshi, and Cash App. El Salvador's national rollout demonstrated real merchant adoption at country scale, and remittance flows from the US to Latin America increasingly route through Lightning-enabled apps.

Beyond Lightning, Bitcoin scaling in 2026 includes covenants proposals (OP_VAULT, LN-Symmetry, CTV variants) still under debate for a future soft fork, and layered systems like Ark and Fedimint for privacy-preserving batching. None have base-layer consensus changes yet, but ecosystem attention has clearly shifted from pure payments to Bitcoin-native financial applications.

BTCFi — Bitcoin in DeFi

Wrapped Bitcoin has been usable in DeFi since WBTC launched on Ethereum in 2019, but the 2024-2026 wave of BTCFi has been structurally different. New protocols like Babylon, Lombard, Solv, and Stacks let users earn yield on native or programmable BTC without a fully custodial bridge. Babylon in particular introduced Bitcoin staking — using BTC as slashable security collateral for proof-of-stake chains — and grew to over $6 billion in Bitcoin-denominated deposits during 2025.

Runes and Ordinals continue to drive on-chain activity spikes. Ordinals inscriptions turn individual satoshis into non-fungible content anchors; Runes provide a UTXO-native fungible token standard released with the 2024 halving. Both have had cycle-driven volume booms and quiet periods, but 2026 finds both technologies as embedded, if niche, parts of Bitcoin block-space demand.

For readers evaluating exposure, our

guide to Bitcoin custody, staking, and wrapped-BTC risk covers the tradeoffs across Babylon, WBTC, tBTC, and cbBTC in depth. Related: our independent rating of the best Bitcoin wallets for self-custody.

Use cases in 2026

• Store of value. The dominant institutional thesis: digital gold, portable and censorship-resistant, hedge against monetary dilution and sovereign risk.
• Global settlement layer. Cross-border value transfer with finality in roughly one hour, no correspondent banks required.
• Lightning payments. Sub-cent micropayments; remittances; content monetisation; streaming payroll.
• DeFi collateral. Through wrapped and native BTC on Babylon, Lombard, Stacks, and emerging BTCFi rails.
• Programmable inscriptions. Ordinals and Runes as issuance and NFT primitives on Bitcoin L1.
• Corporate treasury reserve. Public companies (Strategy, Marathon, Metaplanet in Japan, Semler Scientific) hold BTC as a Treasury asset.

Risks and what to watch

Bitcoin is not a risk-free asset. Volatility remains structurally high — 60-80% drawdowns from cycle peaks have occurred in every four-year period since 2011. In 2026 specifically, the risks worth pricing are:

• ETF flow reversibility. June 2026 recorded $4.4 billion in net outflows in a single month — the worst on record — following the Strategy sale disclosure. The ETF wrapper is not sticky in the way that early bulls hoped.
• Miner fee-revenue transition. Post-2028 halving, block subsidy drops below 1.6 BTC. If transaction fee revenue does not fill the gap, hashrate could contract meaningfully.
• Regulatory perimeter. The US Strategic Bitcoin Reserve remains a work in progress sixteen months after the executive order; Treasury and Commerce are still disputing operational control. Legislative outcomes remain uncertain.
• Quantum computing. A future practical quantum computer could break the ECDSA signature scheme protecting historical addresses. Migration to post-quantum signatures is a long-lead engineering project.
• Custody concentration. A rising share of BTC sits with a small number of ETF sponsors and custodians — BlackRock, Fidelity, Coinbase Custody. This is not a protocol risk but a market-structure one.

Outlook for Bitcoin in 2026 and beyond

The single most important variable in 2026 is whether spot ETF net inflows resume after the June drawdown. If they do, the structural bid returns and the 2024-2027 cycle plays out roughly on the same shape as prior halvings. If ETF flows stay net-negative or flat for a second full quarter, the market will re-price the ETF wrapper as tactical rather than permanent — and the second-half rally many participants are positioned for may not arrive.

The Bitcoin scaling debate — Lightning versus base-layer covenants versus BTCFi rails — will likely produce a soft-fork proposal cycle into late 2026 or 2027. Whether the community coordinates on OP_CTV, LN-Symmetry, or a hybrid will shape what Bitcoin-native applications look like for the next decade.

The CLARITY Act, still pending Senate floor consideration as of July 2026, would clarify CFTC jurisdiction over Bitcoin as a digital commodity and provide clear registration paths for exchanges and custodians. Passage would be a mid-cycle tailwind; failure would leave the current patchwork in place.

Every metric that matters for Bitcoin — hashrate, active addresses, node count, Lightning capacity, ETF AUM, corporate holdings — is meaningfully larger in July 2026 than at the same point in any previous cycle. Price is the last thing to reflect what has already happened structurally.