What is Bitcoin?
Seven years later, again.

What is Bitcoin? I have been asked that question several dozen times in the last seven years. The textbook answer is easy to recite: decentralized, peer-to-peer electronic cash, 21 million hard cap. But the thing you actually need to understand is not those four phrases. It is why this thing survived. The version I want to tell you is the one I learned watching the price collapse to $3,200 in December 2018, and then watching the network keep running anyway.

The textbook definition, and then past it

The official line, from Satoshi Nakamoto's nine-page white paper in 2008, is that Bitcoin is a peer-to-peer electronic cash system. In December 2018, with BTC at $3,200, almost nobody inside crypto was even saying that out loud — the group chats had gone quiet, the influencer accounts had pivoted to other things, and the network just kept producing blocks every ten minutes like a freight train no one was watching. What Satoshi actually did in that paper was solve a problem that computer scientists had been stuck on since the 1980s: how do you get a group of strangers, with no central authority sitting above them, to agree on who owns what?

You do not need the cryptographic details. What you need to know are these five facts:

• There is a ledger somebody is keeping — except "somebody" is tens of thousands of independent machines around the world, each holding its own copy. Changing one copy does nothing; you have to convince the majority of them.
• The ledger only records transfers, not identities — your "account" is a string of letters and numbers called an address.
• The right to write the next page is competed for — by raw compute. Whoever first solves a specific number puzzle gets to write the next block. That is mining.
• Capacity is intentionally limited — one block roughly every ten minutes. That makes transfers slow on purpose; in return you get an enormous attack surface to assault.
• Total supply is capped at 21 million BTC — hard-coded into the protocol, with issuance cut in half every four years.

None of those rules have changed since January 3, 2009, when Satoshi mined the genesis block. As I write this in 2026, the Bitcoin network has not stopped for a single second, has never been successfully attacked at the consensus layer, and has never had its supply cap altered. It is, by a wide margin, one of the longest continuously running production systems in the history of computing.

2018 was the year I actually understood Bitcoin

Why BTC has not gone to zero — three things 2018 taught me

One · mining cost sets a price floor

Mining BTC costs electricity. Every machine has a per-day energy bill that does not care about the spot price. When BTC drops to the level where the BTC you mine no longer covers your power, miners switch off. Miners switching off means supply to market goes down — which actually stabilizes the price, instead of accelerating the decline.

I checked the numbers in late 2018 because I wanted to know if my position was about to disappear. The dominant mining rigs of that era had a shut-down price somewhere between $3,500 and $4,000. When BTC hit $3,200, small farms in Hainan and Sichuan went dark in batches — and then the price bounced. It never broke $3,200 again. That is not coincidence. That is physics. Energy is a cost floor, and a cost floor is one of the few honest things in any market.

Two · there is a cohort of holders that simply will not sell

On-chain data has a metric called "coin age" — how long since the last time a given UTXO was moved. At every cycle bottom, the share of supply that has not moved in more than a year tends to climb above 60%. Translated: more and more BTC is sitting in cold storage, untouched. Some of it belongs to people who lost their keys. Some belongs to early-cycle believers who will not sell at any reasonable price. Some belongs to institutional cold custody.

The circulating float keeps shrinking. That is why late-stage bear markets stop falling. Everyone who wants to sell has already sold. What is left is structural holders, and structural holders do not provide marginal supply. The chart looks flat, the press calls it dead, and quietly the available float is contracting under the surface.

Three · network effects compound

Look at where BTC is held today. MicroStrategy (now legally Strategy), Tesla and Coinbase have put it on the balance sheet of US-listed companies. El Salvador and the Central African Republic adopted it as legal tender. The US SEC approved 11 spot BTC ETFs in January 2024 — BlackRock, Fidelity and the rest of the trillion-dollar asset managers walked through that door within months. Dozens of the world's hundred largest hedge funds now hold BTC in some sleeve.

Every additional institution, country and ETF raises the floor a little. Because if BTC ever did go to zero, every dollar that walked in has to be written off — and that political cost works in the opposite direction, providing structural support. It is the "too big to fail" logic, except instead of being granted by a regulator it has been earned by sheer number-of-holders growth across a decade.

When should you buy? Honestly.

My answer is dollar-cost averaging — a fixed amount on a fixed day every month, regardless of where price is. That sounds unbearably boring. Across seven years I have tried every clever buying scheme I could find, and DCA has been the most consistent thing I ever did.

The reason is simple. You cannot pick bottoms. You think $60K is the top — it runs to $70K. You think $30K is the bottom — it cuts to $25K. Professional fund managers who do this full-time miss the bottom. You will too. So stop trying.

The "2020-2024 annualized" column above is a rough estimate, not a precise backtest. But the directional point holds: on an asset with a long-term uptrend, mechanical DCA outperforms most of the clever timing strategies you can talk yourself into.

Hold vs. trade — the gap is bigger than you think

Holding is a bet that this thing still exists in three years

When you hold BTC long term, the question you are answering is not "will it go up tomorrow." It is "in three to five years, will humans still need an asset that no government controls?" If your answer is yes, BTC is currently the only candidate that qualifies on durability, liquidity and mathematical scarcity.

Gold has played that role for roughly four thousand years. On three specific axes — resistance to seizure, ease of cross-border movement, mathematical guarantee of supply — BTC is structurally stronger than gold. That is why "digital gold" has gone from being a skeptical critique to the default consensus framing among large allocators. The phrase started as an insult and ended as a thesis.

Trading is a bet on next week's price action

Short-term traders are betting on sentiment, liquidations, news, technical patterns — variables that re-roll every day. To do this with positive expectancy, you need 24/7 screen time, exceptional discipline, and the emotional capacity to be wrong loudly and often.

I have watched my Twitter circles for years. The share of three-year-active retail traders who are still in the game and still profitable is, charitably, under 5%. The modal trajectory is account blown, mindset shattered, never touches crypto again. Long-term holders at least survive to the next bull market. That alone puts you ahead of most participants.

The traps every beginner falls into

1. Putting your entire savings into BTC. That is gambling, not investing. A defensible allocation is whatever you can lose without altering your life. For most people that is 5-20% of total assets.
2. Staring at the chart all day. Watching minute-by-minute price action is how you make panicked decisions. I have a friend who bought in 2020, watched the price daily for a year, sold when it had doubled, then watched it triple again from there. He has not touched crypto since.
3. "Insider tips." Ninety-nine percent of what people call insider information is either an outright scam or news that has been fully priced in. If you hear it, you are the exit liquidity, not the early entry.
4. Keeping coins on an exchange forever. After FTX collapsed in November 2022, I no longer leave anything I care about on a centralized exchange. Buy, then move it to self-custody. That is a baseline competency, not paranoia. See the wallet piece.
5. Chasing "the next Bitcoin." The most dangerous misconception in this space. Across the last decade, roughly ten thousand projects have been pitched as "the next Bitcoin." Bitcoin is still here. They mostly are not. Instead of looking for the next one, buy the one that already won.

§US/EU · the part that does not appear in the Chinese version

Everything up to here applies whether you are buying BTC through Coinbase in San Francisco or through Bybit in Dubai. But if you are reading this from the United States or the European Union, your access path, tax treatment and self-custody choices look materially different from a 2017-era Korean retail trader's. This section is the lens for that.

Spot Bitcoin ETFs · the January 2024 access shift

On January 10, 2024, the SEC approved 11 spot Bitcoin ETFs in a single batch. BlackRock's IBIT, Fidelity's FBTC, Ark/21Shares' ARKB, Bitwise's BITB, Grayscale's converted GBTC and several smaller issuers. Within twelve months, IBIT alone had crossed $50 billion in assets under management — the fastest-growing ETF launch in US history. Fidelity's FBTC reached roughly $20 billion in the same window. GBTC, which had carried a 2% fee from its trust-era pricing, immediately started bleeding billions to lower-fee competitors; legacy holders rotated into IBIT and FBTC, and the fee war compressed expense ratios into the 0.12-0.25% band.

For a US-domiciled investor, that approval changed the access question entirely. You no longer needed a Coinbase account, a private key, or any exposure to offshore counterparty risk to get BTC exposure. A regular Fidelity, Schwab or Vanguard brokerage account — and crucially, any 401(k) or IRA wrapper that allowed ETF holdings — could now buy IBIT the same way it buys SPY. The behavioral implication is large: trillions of dollars sitting in tax-advantaged accounts that were institutionally barred from buying spot BTC are now structurally able to participate. That capital does not behave like retail.

MicroStrategy (Strategy) as the public-market BTC proxy

Michael Saylor's MicroStrategy — now formally renamed Strategy — has been the most aggressive corporate accumulator of BTC since August 2020. As of early 2026, Strategy holds over $50 billion in BTC at a blended cost basis below $70,000. The mechanic is unusual for a US-listed equity: the company issues low-coupon convertible notes and at-the-market equity, uses the proceeds to buy spot BTC, and holds the position. Every halving, Saylor has accelerated rather than throttled purchases, on the explicit thesis that supply is being cut while institutional demand is rising. Even if you never own MSTR directly, it matters because it is the single largest non-ETF equity-funded marginal buyer of BTC, and its purchases visibly move spot price.

Spot BTC ETFs vs. futures-based ETFs · the roll-cost drag

Before January 2024, the only US-listed Bitcoin ETF was BITO (ProShares Bitcoin Strategy ETF), which holds CME Bitcoin futures rather than spot BTC. Futures-based ETFs suffer a structural drag: every month they have to "roll" expiring contracts into the next month, and during contango (the normal state for BTC futures) that roll cost destroys roughly 5-10% of annualized return relative to spot. Two years after spot ETFs launched, the math is clear: IBIT and FBTC have outperformed BITO by a wide margin, and there is no remaining reason for a US retail investor to use the futures-based product. If you bought BITO before spot ETFs existed, the rational move is to migrate to spot. (Talk to a tax professional about the realized gain — that is what your broker is paid to help with.)

US tax · long-term capital gains, and why holding 12 months matters

The US tax code rewards long holds. Gains on BTC held more than 12 months qualify for long-term capital gains rates: 0%, 15% or 20% depending on income, plus 3.8% NIIT for higher earners. Sales inside 12 months are taxed as ordinary income — up to 37% federal at the top bracket, plus state, plus NIIT. The structural implication for halving-aware investors is direct: if you buy in the cycle-bottom window and hold through the post-halving window, you have almost mechanically crossed the LTCG threshold by the time you sell into strength. The same trade executed inside a 12-month round trip is taxed at more than double the effective rate. One useful note for 2026: the wash-sale rule does not currently apply to crypto, which means realizing losses to harvest tax basis is legal in BTC in a way it is not in equities. That gap may close. While it is open, it is the cleanest tax-management tool you have.

State-by-state · where US BTC holders actually live differently

Federal tax is one thing; state regimes differ meaningfully. New York's BitLicense regime restricts which exchanges and stablecoins are available to NY residents — Kraken pulled spot trading from New York, several stablecoins are not listed for NY-based accounts. Wyoming has been deliberately crypto-friendly, with a Special Purpose Depository Institution charter that enables crypto-native banks like Custodia and Kraken Financial Services. Texas has become a hub for industrial-scale BTC mining due to deregulated power markets — most US-listed public miners now operate significant Texas capacity. California's DFPI runs an active enforcement regime under the Digital Financial Assets Law. None of this changes federal tax, but it changes what services you can use day-to-day.

Self-custody for US holders · once your stack crosses $100K

For US readers specifically, my rough threshold is this: anything below $100,000 in BTC is fine to keep at Coinbase or via a spot ETF in your brokerage account. Once your stack crosses $100,000, the math changes — the cost of even a low-probability exchange failure starts to matter relative to the friction of self-custody. Mainstream hardware-wallet picks are Ledger and Trezor. The third-party industry standard for higher-net-worth setups is Casa (multi-sig service with key recovery) or Unchained Capital (collaborative custody with US-based key agents). The point of multi-sig is to remove single points of failure — no single device, key or counterparty can move your BTC. The tradeoff is operational complexity, which is exactly why I recommend the $100K threshold before you take it on: under that number, custodial risk is probably smaller than operator-error risk in your own setup.

The 2024-2025 US political backdrop

The 2024 US election cycle was the first one where BTC was an explicit policy topic. The Trump administration ran on an openly pro-BTC platform: Strategic Bitcoin Reserve proposals, friendlier SEC enforcement, ending Operation Choke Point 2.0 (the unofficial debanking of crypto firms). With Paul Atkins installed as SEC chair in 2025, the regime shifted from Gensler-era "almost-everything-is-a-security" enforcement to a clearer rules-based regime that distinguishes investment contracts from digital commodities. For a US holder, the practical near-term effects have been: more product launches (Solana ETF, Litecoin ETF, basket ETFs all moved forward), fewer Wells notices against US-domiciled exchanges, and a clearer path for BTC as collateral inside the regulated US banking system. Regulatory regime is a slow-moving variable that can flip every four to eight years. Position accordingly.

The MiCA effect · what changed for EU readers

Markets in Crypto-Assets Regulation (MiCA) became fully applicable across the EU at the end of December 2024. Any exchange operating in the EU now requires a CASP (Crypto Asset Service Provider) authorization, must publish a whitepaper for listed tokens, and follows MiCA's stablecoin reserve rules. Binance restructured its European footprint into nationally licensed entities (Binance France, Binance Spain, etc.). Kraken, Bitstamp and Coinbase Europe are all CASP-authorized. The UK runs a separate post-Brexit regime under the FCA — UK readers should follow FCA promotional rules rather than MiCA. National-level tax still varies widely: Germany taxes BTC at zero after a 12-month hold for individuals; Portugal moved from tax-free to a 28% rate from 2023 but stays favorable for long holders; France taxes crypto-to-crypto disposals; Italy applies 26% on gains above €2,000. There is no MiCA-level tax harmonization, which means your jurisdiction still drives your effective return materially.

Three practical rules for a US/EU reader

Pull all of the above together and the playbook compresses into three lines. First, put your base allocation in a spot ETF inside a tax-advantaged account — IRA or 401(k) in the US; a CASP-authorized broker plus the local tax-wrapper equivalent in the EU. The LTCG calendar and the halving calendar are the same calendar; let them work together. Second, once your stack crosses six figures, move the long-horizon portion into self-custody — Ledger or Trezor at minimum, Casa or Unchained multi-sig once you cross seven figures. Custodial risk is real but slow; operator-error risk is real but front-loaded. Sequence the transition deliberately. Third, never sell into a cycle peak in a single block. Distribute the exit across five tranches starting 12-18 months after the halving. Every cycle has a "I thought it was the top and then it rallied another 50%" leg. Do not let that leg take all of your profit with it.

Does BTC actually have value? Honest answer.

This is the eternal argument. One camp says BTC has no intrinsic value: unlike gold you cannot make jewelry from it; unlike a stock there is no company underneath; unlike a house you cannot live in it. The other camp says BTC's value is exactly its scarcity, portability and censorship resistance.

My honest read after seven years: value is whatever the consensus says it is. A dollar is worth a dollar because we collectively agree it can buy things. A gram of gold is worth a gram of gold because four thousand years of human history have agreed it is precious. BTC currently has a consensus footprint measured in trillions of dollars. That consensus might keep growing. It might also collapse one day. I do not know which.

What I do know — having watched it through seven years — is that the consensus has not contracted. Every cycle somebody declares BTC will go to zero. Every cycle that has been wrong. And every cycle the holder mix gets one step more institutional: retail investors first, then public companies, then nation-states, then (plausibly) central banks. If that trajectory continues, the floor of every cycle keeps stepping higher even if the multiple keeps stepping lower.

Closing notes

Bitcoin is not complicated. What is complicated is holding it through a violently volatile market. That part took me seven years.

For a beginner: buy a small amount, move it to your own wallet, and forget about it for three years. Three years from now, come back to this page. You will understand what I am saying.

If you want to keep going, read the Ethereum piece — that is the second-most-important chain after BTC. Or skip to the bull-vs-bear note and pick up a handful of simple signals. They will not make you a great trader, but they will probably stop you from buying at the top.