What Is Bitcoin?
Bitcoin (BTC) is the first decentralized cryptocurrency, created in 2009 by an anonymous entity known as Satoshi Nakamoto. Its white paper, published on October 31, 2008, describes a "peer-to-peer electronic payment system" that operates without a trusted intermediary (bank, government).
Bitcoin is built on three fundamental pillars:
- Limited supply: there will never be more than 21 million bitcoins. As of 2026, approximately 19.8 million are already in circulation.
- Decentralization: no central authority can change the network's rules, censor a transaction, or freeze funds.
- Transparency: all transactions are publicly visible on the blockchain, verifiable by anyone.
Simplified Technical Overview
Mining (Proof of Work)
Bitcoin uses a consensus mechanism called Proof of Work. Specialized computers (miners) solve complex mathematical problems to validate transactions and create new blocks. As a reward, they receive newly created bitcoins.
- Average time per block: 10 minutes
- Current reward: 3.125 BTC per block (since the April 2024 halving)
- Network power: approximately 600 EH/s (exahash per second) in 2026
Halvings
Every 210,000 blocks (approximately every 4 years), the miners' reward is cut in half. This is the halving:
| Halving | Date | Reward | BTC Price (approximate) |
|---|---|---|---|
| 1st | November 2012 | 25 BTC | $12 |
| 2nd | July 2016 | 12.5 BTC | $650 |
| 3rd | May 2020 | 6.25 BTC | $8,700 |
| 4th | April 2024 | 3.125 BTC | $64,000 |
| 5th (estimated) | ~2028 | 1.5625 BTC | ? |
Historically, each halving has been followed by a significant price increase within the following 12 to 18 months, driven by the reduction in new supply.
Price History
Bitcoin has experienced spectacular bull and bear cycles:
| Period | Low Price | High Price | Change |
|---|---|---|---|
| 2011 | $0.30 | $31 | +10,233% |
| 2013 | $13 | $1,100 | +8,362% |
| 2017 | $1,000 | $19,800 | +1,880% |
| 2021 | $29,000 | $69,000 | +138% |
| 2024-2025 | $38,000 | $108,000 | +184% |
Annualized return since 2011: approximately +130% per year (with extreme volatility).
Volatility remains Bitcoin's defining characteristic: drops of 50 to 80% are common within each cycle. Investors must be psychologically prepared to see their portfolio temporarily lose half its value.
Spot Bitcoin ETFs
Since January 2024, Spot Bitcoin ETFs have been available in the United States, and progressively in Europe. These exchange-traded funds allow you to invest in Bitcoin without directly holding the cryptocurrency.
Advantages of Bitcoin ETFs
- Simplicity: purchase through a standard brokerage account, without needing a wallet or private key
- Regulation: products approved by regulators (SEC, AMF)
- PEA tax wrapper: some European crypto ETFs may eventually become eligible for the PEA (Plan d'Epargne en Actions, a tax-advantaged stock savings plan in France)
- Security: no risk of losing private keys
ETFs Accessible from France
| ETF | Issuer | Annual Fees | Exchange |
|---|---|---|---|
| Invesco Physical Bitcoin | Invesco | 0.39% | Xetra |
| 21Shares Bitcoin ETP | 21Shares | 0.21% | Euronext Paris |
| CoinShares Physical Bitcoin | CoinShares | 0.35% | Xetra |
| WisdomTree Physical Bitcoin | WisdomTree | 0.35% | Euronext Paris |
Investment Strategies
Strategy 1: DCA (Dollar Cost Averaging)
DCA involves investing a fixed amount at regular intervals, regardless of the price. It is the most suitable strategy for the majority of investors.
Example: investing 200 EUR per month in Bitcoin over 4 years.
Historically, a monthly DCA into Bitcoin over any 4-year period has always been profitable (except when starting at the 2021 peaks with too short a time horizon).
Strategy 2: Lump-Sum Investing
Investing a large amount all at once. Statistically more profitable (the market rises more often than it falls), but psychologically challenging in the event of an immediate decline.
Strategy 3: HODL (Hold On for Dear Life)
Buy and hold for the very long term (at least 5 to 10 years), without ever selling. This strategy relies on the conviction that Bitcoin will continue to appreciate across successive halving cycles.
DCA Simulation
Investing 100 EUR/month over 5 years (2020-2025):
- Capital invested: 6,000 EUR
- Portfolio value at end of 2025: approximately 18,000 to 22,000 EUR
- Return: +200 to +267%
- Annualized performance: approximately +25 to 30%
Bitcoin as a Store of Value
Bitcoin is often compared to gold as a store of value:
| Criterion | Gold | Bitcoin |
|---|---|---|
| Limited supply | Yes (mining) | Yes (21 million, mathematical) |
| Divisibility | Difficult | Down to 0.00000001 BTC (1 satoshi) |
| Portability | Low (weight) | Total (digital) |
| Verifiability | Costly | Instant (blockchain) |
| Volatility | Low (10-15%/year) | Very high (50-80%/year) |
| Track record | 5,000 years | 17 years |
Bitcoin is a young asset: its volatility should decrease as market capitalization and adoption grow, but it remains for now a high-risk asset.
Risks Specific to Bitcoin
- Extreme volatility: drops of 50 to 80% are historically normal
- Regulatory risk: potential bans in certain countries (already the case in China)
- Technological risk: while highly unlikely, a cryptographic flaw would be catastrophic
- Loss risk: loss of private keys = permanent loss of funds (approximately 3.7 million BTC are believed to be lost forever)
- Environmental risk: mining consumes as much electricity as a country like Norway, attracting societal criticism
What Share of Bitcoin in Your Portfolio?
Recommendations from wealth managers in 2026:
- Conservative profile: 1 to 3% of total assets
- Balanced profile: 3 to 5%
- Dynamic profile: 5 to 10%
- Recommended maximum: never exceed 10% of your assets, regardless of conviction
For a portfolio of 100,000 EUR, a 5% allocation represents 5,000 EUR in Bitcoin.
Conclusion
Bitcoin is a unique asset in financial history: digital, decentralized, with a limited supply and censorship-resistant. After 17 years of existence, it has survived every crisis and continues to be adopted by institutions (ETFs, corporate reserves, regulatory frameworks). For individual investors, a long-term DCA strategy remains the most suitable approach to capture upside potential while mitigating volatility. Limit your exposure to a reasonable fraction of your overall portfolio.