That is Bitcoin’s first danger: it can cause someone to lose a huge amount of money without its network breaking down.
But volatility is only part of the problem. Bitcoin operates without a bank capable of reversing a transaction. Losing a private key can be permanent. An exchange can go bankrupt. Malware can empty a wallet. Leverage can liquidate a position within minutes. Even the public visibility of a large BTC fortune can now create a physical risk.
That said, simply saying “Bitcoin is dangerous” would be misleading. A distinction must be made between the Bitcoin protocol and the services and behaviors built around it. The network has operated since 2009 without a central bank and continues to settle transactions. Many of the dangers users encounter arise elsewhere: in the price, intermediaries, custody or speculation.
Bitcoin can lose 70% without being broken
The first thing an investor needs to understand is fairly brutal: a fall in Bitcoin’s price does not imply that Bitcoin itself has malfunctioned. Our article on the reasons behind Bitcoin’s volatility shows precisely how liquidity, market psychology, speculation and the macroeconomic environment can move its price sharply.
The 2021–2022 example remains instructive.
According to the AMF, BTC was worth approximately 56,301 euros in November 2021. On December 25, 2022, it was worth only around 15,421 euros. The loss approached 73%. Bitcoin subsequently rebounded and exceeded 106,000 euros in October 2025.
An investor with 10,000 euros at the peak would therefore have seen their position fall to around 2,700 euros at the low, even before taking fees into account.
Psychologically, that is enormous.
And returning to breakeven does not require a 73% rise. After a 73% decline, an asset must gain approximately 270% to return to its initial price.
This mathematical detail explains why drawdowns are so difficult to endure.
Bitcoin can therefore be dangerous for someone who needs their money in the short term. Savings intended for rent in six months, education, a medical emergency or a major repayment do not have the same time horizon as capital that can remain invested for five or ten years.
Volatility mainly turns time into a risk.
You can be right about Bitcoin in the long term and still be forced to sell at the worst possible moment.
No central bank guarantees its value
Bitcoin has a characteristic that its supporters regard as a strength: no central bank controls it.
That independence has a downside.
No central bank guarantees a minimum value for Bitcoin either. There is no official mechanism tasked with defending its price at 50,000, 20,000 or 5,000 dollars.
If buyers disappear, the market falls.
Period.
The AMF also points out that Bitcoin is not legal tender in France. A merchant is not required to accept it as payment, and BTC does not benefit from the same protections as a bank deposit.
More importantly for investors, crypto-assets held with an intermediary do not automatically benefit from the Deposit and Resolution Guarantee Fund, unlike traditional bank deposits.
The presence of a major platform, an elegant application and a euro-denominated account can create the impression that you are using a bank.
It is not the same thing.
Since July 1, 2026, providers legally offering crypto services in France have been required to hold European CASP status under MiCA. This regulation improves oversight of intermediaries, but it does not turn Bitcoin into a guaranteed product.
The price can still collapse.
Regulation protects against certain behaviors by service providers.
It does not protect against the market.
Controlling your bitcoins means taking responsibility for your mistakes
Self-custody is often presented as one of Bitcoin’s major strengths.
With the right private keys, a user can control their BTC directly without asking a bank or exchange for permission.
That is powerful.
It is also unforgiving.
The AMF points out that a private key provides access to assets and authorizes their use. Losing it can therefore mean permanently losing access to the corresponding bitcoins.
There is no universal “forgot password” button.
The recovery phrase, or seed phrase, adds another responsibility. Anyone who obtains these words can often recreate the wallet and move the funds.
Hence a basic rule: a seed phrase should never be sent by email, WhatsApp or Telegram, stored in an easily accessible screenshot or shared with someone claiming to be technical support.
And even dedicated hardware does not eliminate every risk.
In August 2026, a vulnerability affecting certain generations of Coldcard wallets led to approximately 233,000 BTC being moved, previously attributed to long-term holders. The weakness concerned the generation of certain seeds, not the Bitcoin protocol itself.
The distinction is essential.
Bitcoin can be secure.
The device used to manage the keys may not be.
Self-custody therefore eliminates some counterparty risk, but shifts that responsibility to the user, their hardware and their procedures.
Leaving your BTC on an exchange creates another risk
The solution may seem obvious: do not manage the keys yourself and leave Bitcoin on a platform.
This solves some problems.
And creates others.
When the platform holds the keys, the user depends on it to recover their BTC. A bankruptcy, hack, internal fraud, regulatory freeze or poor management can become their problem.
Crypto’s history is full of reminders: Mt. Gox, FTX and several much smaller exchanges have shown that an interface displaying a balance does not always equal assets that are actually available.
The risk still exists today.
In Poland, the Zondacrypto case has resulted in more than 3,600 complaints and at least 350 million zlotys in estimated losses. The investigation notably refers to a cold wallet containing approximately 4,500 BTC that the exchange allegedly lost access to as early as 2022.
Users therefore face a trade-off.
Self-custody: they control the keys directly, but their mistakes can be irreversible.
Exchange: a company simplifies custody, but becomes a point of dependence.
There is no single answer for everyone.
A beginner may be more exposed to self-custody errors. An experienced person keeping a large sum on a single platform may be accepting unnecessary counterparty risk.
The real danger is mainly not knowing which of these risks you are taking.
A Bitcoin transaction is difficult to reverse
In the banking system, a fraudulent payment can sometimes be disputed.
A card can be blocked.
A recent transfer can, in certain circumstances, be subject to an attempted recall.
Bitcoin works differently.
A properly signed and confirmed transaction has no central service capable of deleting it from the ledger simply because the sender made a mistake.
That is an important feature of the system.
It is also a risk.
Sending BTC to the wrong address can become irreversible. Sending funds to a scammer can be irreversible too.
And attackers know it.
Modern campaigns do not always try to break Bitcoin’s cryptography. They attack the user.
Phishing.
Fake customer support.
Malware.
Browser extensions.
Fake wallets.
Software that takes control of the clipboard to replace the copied address.
In August, malware campaigns studied by Huntress targeted wallets and exchange accounts, among other things. The attacker did not need to compromise the blockchain. They only needed to reach the machine providing access to the assets.
This is an important point.
Bitcoin uses extremely robust cryptography.
The user’s computer may be full of dangerous software.
Protocol security does not eliminate the security risks in the surrounding environment.
Scams exploit Bitcoin’s reputation
Bitcoin itself is not a scam.
But its success is an excellent tool for scammers.
A fake adviser may promise automated Bitcoin investments.
A fake platform may display profits that do not exist.
A romance scammer may persuade their victim to transfer crypto gradually.
A fake Elon Musk may promise to double the BTC sent to an address.
The figures provide an idea of the scale.
Chainalysis estimates that crypto scams and fraud may have stolen more than 17 billion dollars in 2025, following the gradual identification of associated addresses. Impersonation scams experienced particularly strong growth.
This does not mean that 17 billion dollars was stolen specifically in Bitcoin.
Illicit activity has also shifted significantly toward stablecoins. Chainalysis estimates that they accounted for 84% of identified illicit crypto volume in 2025.
That is an important nuance.
The danger does not come from Bitcoin as a network.
It comes from the fact that an asset that is easily transferable, global and difficult to recover after payment is also highly suitable for fraudsters.
The best defense is therefore not a better price forecast.
Sometimes, it is simply recognizing that a “guaranteed” return of 5% per week does not exist.
The AMF makes this clear: no serious company can guarantee a minimum return on a crypto-asset investment.
Leverage can turn a small decline into a total loss
Bitcoin is already volatile in the spot market.
Adding leverage means amplifying an asset that did not need any help to move.
Consider a simplified 1,000-euro position.
In the spot market, a 10% decline leaves approximately 900 euros.
With theoretical 10x exposure, an adverse move of this size may be enough to destroy a very large portion of the margin and trigger liquidation, depending on the product, fees and exact liquidation price.
A user can therefore be right about Bitcoin in the long term while losing their entire position because the market temporarily fell.
This is a common paradox.
BTC falls from 85,000 to 76,000 dollars.
The highly leveraged position is liquidated.
Six months later, Bitcoin may be worth 100,000 dollars.
The long-term analysis may have been right.
The trading account, however, no longer exists.
The AMF specifically warns about crypto CFDs and leverage, which are even more dangerous when the underlying asset is already highly volatile. For retail investors, the regulatory leverage limit for crypto-asset-based CFDs is 2 in Europe.
On some crypto platforms outside this framework, however, users may find much more aggressive products.
This is often where the line between investing and gambling becomes very thin.
Buying Bitcoin does not require using leverage in any way.
The two decisions should be kept separate.
Bitcoin also depends on Wall Street and macroeconomics
Bitcoin is decentralized.
Its price does not exist outside the global economy.
Since the arrival of spot ETFs in the United States, this connection with traditional markets has even strengthened.
On May 18, 2026, U.S. spot Bitcoin ETFs recorded 649 million dollars in net outflows in a single session. BlackRock alone accounted for 448 million dollars in withdrawals that day.
These flows illustrate a new risk.
Institutionalization brings major buyers when sentiment is favorable.
It also brings sellers capable of withdrawing several hundred million dollars very quickly.
Add Federal Reserve rates, U.S. inflation, the dollar, the bond market and global liquidity.
Bitcoin can then fall without any bad news directly affecting its network.
In its June 2026 risk mapping, the AMF still noted that crypto-assets remained highly sensitive to changes in the economic and financial environment.
The narrative of an “asset totally independent from traditional finance” must therefore be qualified.
Bitcoin does not depend on a central bank to function.
Its price still depends on decisions made by buyers and sellers who themselves live in the traditional economy.
When the dollar strengthens, bond yields rise or a geopolitical shock pushes investors toward liquidity, BTC can suffer.
Decentralizing the network does not decentralize market emotions.
Holding a large amount of Bitcoin can become a physical risk
A more unusual danger has emerged as the value of crypto portfolios has increased.
Physical violence.
In a traditional bank account, a criminal who forces someone to reveal their password cannot necessarily transfer millions immediately. Banks have limits, anti-fraud systems, delays and blocking mechanisms.
With a crypto wallet directly controlled by the victim, the situation may be different.
Chainalysis estimates that violent attacks against crypto holders reached 58 million dollars stolen in 2025. In 2026, more than 30 million had already been stolen by mid-year. Home invasions accounted for 37% of the incidents identified that year.
These “wrench attacks” represent a fairly brutal limitation of cryptography.
It is extremely difficult to mathematically break a sufficiently robust private key.
It may be much easier to threaten its owner.
This risk mainly concerns people whose crypto wealth is publicly known: entrepreneurs, influencers, traders displaying their portfolios or holders whose identities have been leaked.
Privacy therefore becomes a security measure.
Publicly displaying the exact number of BTC held may satisfy an ego.
It may also publish the size of a potential reward.
Bitcoin makes it possible to become your own bank.
A bank, however, has guards, procedures and secure buildings.
Individuals must think differently.
Bitcoin can also be used for criminal activity
Bitcoin has an important property: the network does not ask why a transaction is being made.
A transaction that complies with the technical rules can be confirmed whether it is used to pay for a computer, transfer savings or move funds derived from criminal activity.
This neutrality is useful to legitimate users.
It is also useful to criminals.
Ransomware, illicit markets, fraud and money laundering therefore use crypto-assets.
However, it would be false to portray Bitcoin as a primarily criminal network.
Chainalysis estimates that illicit addresses received at least 154 billion dollars in crypto in 2025, largely because of the surge in activity linked to sanctioned entities. Despite this record amount, illicit activity still accounted for less than 1% of attributed crypto volume.
The phenomenon is also much less centered on Bitcoin than it once was. Stablecoins accounted for most of the illicit volume identified in 2025.
Bitcoin nevertheless retains an important role in certain areas.
Ransomware received approximately 820 million dollars in on-chain payments in 2025, according to Chainalysis.
This criminal use creates several risks for an honest user.
Bitcoins that have passed through addresses associated with sanctions, a hack or ransomware may trigger additional checks with certain intermediaries.
Technically, 1 BTC remains 1 BTC within the protocol.
In the regulated economy, the coins’ history may matter.
This is a risk that is often overlooked when Bitcoin is presented as perfectly fungible.
Its energy cost remains a real issue
Bitcoin secures its network through Proof of Work.
Miners use specialized machines that consume electricity to take part in the competition to produce new blocks.
This energy expenditure is not an accident.
It is part of the network’s security mechanism.
It nevertheless raises an important environmental and economic question.
The Cambridge Centre for Alternative Finance estimated Bitcoin’s annualized electricity consumption at approximately 138 TWh as of June 30, 2024, equivalent to around 0.54% of global electricity consumption. Its model subsequently indicated approximately 183 TWh at the end of 2024 as the hashrate increased sharply.
The picture is not entirely negative, however.
Cambridge estimated that so-called sustainable energy sources accounted for 52.4% of the electricity mix among surveyed miners, including 42.6% renewables and 9.8% nuclear power. Natural gas accounted for 38.2%, while coal had fallen to 8.9%.
The debate therefore cannot be reduced to “Bitcoin is destroying the planet” or “Bitcoin uses only surplus energy.”
Both formulations are too simplistic.
The network consumes a great deal of electricity.
The source of that electricity varies greatly by region.
And the mining industry remains highly sensitive to energy prices. Competition with artificial intelligence data centers is already pushing some Bitcoin miners toward cheaper energy sources.
For investors, this risk is indirect.
If electricity becomes more expensive, miners’ margins shrink. The least efficient companies may shut down, sell BTC or relocate their infrastructure.
Bitcoin generally continues to adjust its difficulty.
But the network’s economics remain closely tied to the physical world.
Regulation can change very quickly
Bitcoin was designed to operate without central authorization.
The users and companies built around Bitcoin, however, operate within jurisdictions.
A state can regulate exchanges.
Tax capital gains.
Restrict certain derivatives.
Impose identity checks.
Restrict mining.
Prevent certain institutions from offering certain services.
This does not necessarily destroy Bitcoin.
It can nevertheless radically change how easy it is to use Bitcoin and affect its price.
Europe provides a good example with MiCA.
Since July 1, 2026, France’s transition period has ended. Companies wishing to provide crypto services must hold the appropriate CASP status.
This is generally positive for consumer protection.
But it serves as a reminder that rules can change while an investor is holding their assets.
Taxation is another example.
A gross return of 50% does not necessarily mean 50% is retained after selling, fees and taxes.
And the rules vary from country to country.
Someone living in France, the DRC, the United States or Portugal does not necessarily have the same obligations.
Bitcoin is global.
Taxation is not.
The danger therefore does not lie solely in a hypothetical total ban.
A succession of smaller changes can alter profitability, access to banking services or the services available.
Quantum risk exists, without any demonstrated urgency
This is probably the most spectacular technical risk.
Bitcoin notably uses elliptic-curve cryptography to allow users to prove that they control certain keys without directly revealing their secrets.
A sufficiently powerful quantum computer could theoretically threaten certain cryptographic signatures.
Would that mean a quantum computer could drain Bitcoin wallets today?
No.
Current machines do not yet have the power, stability and number of logical qubits required to carry out such an attack at scale.
The risk is longer term.
It nevertheless deserves preparation before it becomes urgent.
Public keys already exposed on the blockchain could be of particular interest in a future where a cryptographically relevant quantum computer becomes available. Reused old addresses would be a particular area to monitor.
The main problem is not only developing new quantum-resistant signatures.
Bitcoin evolves slowly by design.
Changing such a fundamental part of the protocol requires broad consensus among developers, users, companies, miners and wallet providers.
That takes time.
In 2026, governments also accelerated their own preparations for post-quantum cryptography. Our report on the accelerating quantum race and the transition to post-quantum protections noted that this threat also affects banks, government administrations and secure communications, not just Bitcoin.
It would therefore be excessive to present quantum computing as a reason to flee BTC today.
Ignoring it completely would be just as imprudent.
Is Bitcoin ultimately dangerous?
Yes, Bitcoin can be dangerous. But not always for the reasons people imagine. The protocol does not need to be hacked for an investor to lose 70%. It does not need to stop operating for an exchange to go bankrupt. It does not need a vulnerability for a user to hand their seed phrase to a scammer. It does not need to malfunction for a 20x trader to be liquidated.
And it can continue producing one block after another while its price collapses. That is precisely what makes Bitcoin risk distinctive. Technology and investing are two different subjects.
For a user who can properly secure their keys, avoid leverage, check their intermediaries and invest only capital they do not need quickly, several dangers can be significantly reduced.
They never disappear completely. Volatility remains. Regulatory changes remain. Long-term technological risk remains.
Human risk remains too. And this last category is probably the hardest to eliminate. Investors make mistakes when they are afraid. They also make mistakes when they become overconfident. At 20,000 dollars, some refuse to buy because Bitcoin appears dead.
At 100,000 dollars, those same people may want to borrow money to buy because Bitcoin appears invincible. The protocol has not changed between the two.
Psychology has. That is ultimately the best answer to the question, “Why is Bitcoin dangerous?”
Bitcoin gives its owner a great deal of freedom and very little room for error.
You can control your money directly and transfer it globally while avoiding certain intermediaries.
In return, no central bank guarantees its price, no Bitcoin hotline can recover a lost private key and no network administrator can reverse a mistaken transaction.
This asymmetry does not make Bitcoin bad.
It makes Bitcoin demanding.
And for someone who does not understand what they are buying, uses leverage or commits money they will soon need, it can indeed become dangerous.
