How Cryptocurrency Owners Lose Fortunes Due to One Mistake in the Blockchain

Cryptocurrency owners lose fortunes not only after hacks: sometimes a wrong swap route, an error in the address, choosing the wrong network, or giving unnecessary permissions to a smart contract is enough for investments worth millions of US dollars to practically disappear after a single signature.

Cryptocurrency gives the user direct control over their money, but it also shifts almost all responsibility onto the owner. The blockchain does not evaluate a person's intentions. If the parameters are confirmed, the network executes the command as it was signed: it sends tokens to the specified address, conducts a swap based on available liquidity, or allows the contract to use the assets.

This is why an error in a wallet interface or on a DeFi platform can cost more than ordinary market volatility. Even if the asset remains valuable in accounting, it is often impossible to recover it after a wrongly signed operation.

Most often, such losses are caused by several scenarios: phishing, address poisoning, incorrect network selection, incorrect permissions for smart contracts, errors in swap routes, and social engineering. The scale can be enormous: a single signature or a copied address in such situations has led to losses of millions and tens of millions of dollars.

The price of crypto assets can fall not only due to ordinary volatility. Market pressure is intensified by hacks, regulatory bans, technical failures, mass liquidations of positions, and a lack of liquidity—therefore, a technical error sometimes turns into a personal portfolio crash for the owner.

A Large Swap Can Destroy the Price by Itself

One recent case occurred in the Solana network. A user attempted to swap about 7.8 million STONKS tokens, valued at approximately 1.8 million dollars. However, the transaction went through a Raydium route with extremely low liquidity. In the end, the user received only about 26.8 RAY, which is roughly 25 dollars.

From a technical standpoint, everything went correctly: tokens were deducted, the swap occurred, and the result was recorded on the blockchain. The error was not in the network's operation, but in the execution price. The liquidity pool simply could not handle such a volume without a sharp distortion.

When a transaction goes through pools, a large order changes the balance of assets within them. If the swap volume is much larger than the available liquidity, the user’s order starts to push the price against itself. As a result, the final amount may turn out to be incomparable to the calculated value of the position.

A similar story became particularly noticeable in March 2026. A user attempted to swap USDT worth about 50 million dollars on AAVE through the Aave interface. After the transaction was completed, they were left with only 324 AAVE worth about 36,000 dollars.

The Aave interface did not hide the risk. The project's founder, Stani Kulechov, explained that the system warned the user about extreme slippage due to the unusually large order and required them to confirm their acceptance of the risk separately. The user checked the necessary box on their mobile device and proceeded with the operation.

Later, Aave developer Martin Grabina clarified that the key reason for the losses was the impact of the transaction itself on the price: the order was too large relative to the available liquidity.

CoW Swap stated that it found no signs of hacking or malicious actions. The transaction was executed according to the parameters of the signed order. Later, Aave decided to attempt to return approximately $600,000 in fees that were generated from this transaction.

In November 2025, a similar error occurred with a Cardano holder. He exchanged 14.4 million ADA worth about $6.9 million for only 847,695 USDA and lost approximately $6.05 million due to a lack of liquidity. Prior to this, the wallet conducted a small test transaction, but it did not indicate what would happen when exchanging the entire amount.

Incorrect Address Turns Transfer into Irrecoverable Loss

An even more dangerous situation arises when the blockchain executes the operation correctly, but the money goes to the wrong recipient. In May 2024, the owner of 1,155 WBTC worth about $68 million fell victim to an address poisoning attack. This is an attack where the attacker inserts an address into the wallet's history that visually resembles the real one.

The scheme does not require stealing a private key. The attacker creates a similar address and sends a small amount from it to the victim's wallet. Then the owner, checking only the beginning and end of the string, copies the fake address from the transaction history and transfers funds to it. In this case, 1,155 WBTC were sent to the incorrect address, and later the value of these assets was estimated at about $71 million.

The transaction history, which many use as protection against typos, becomes a tool for deception in such an attack. It is enough not to check the entire sequence of characters, and the network will send assets without question to the address indicated by the signer.

Sometimes a disaster does not even require a malicious actor. In 2024, a user named Renzo confused his own wallet address with the address of a related technical smart contract while copying and sent assets worth about $25 million there. After unsuccessful attempts to recover the funds, he offered $2.5 million to anyone who could help regain access to them.

Not only private users make mistakes. Wintermute provided the developers of Optimism with the address of an Ethereum multi-signature wallet but did not check whether it could control the same address on the Optimism network. There were test transfers before the main operation, but the problem only became apparent after sending 20 million OP.

Danger May Lie Not in the Transfer, but in the Approval

Not all losses begin with a direct token transfer. In DeFi, users often sign approvals allowing smart contracts to work with their assets. Such consent can remain active long after the completion of a specific operation.

A brief summary of this case: January 2026; exploitation of a vulnerability in the DEX aggregator SwapNet, integrated with Matcha Meta; approximately $13.4 million in losses; reason --- protocol vulnerability and direct approvals instead of One-Time Approval; nearly the entire amount, about $13.34 million, was attributed to one wallet.

This is the main risk of approvals. A signature may not immediately deduct funds but keep external contracts accessible to assets for weeks or months. When the contract gains the ability to use this approval, the wallet owner may have long forgotten that it was ever granted.

Why Blockchain Does Not Save from Human Errors

All these cases share one thing in common: the network, in most episodes, did exactly what it was instructed to do. The swap went through available liquidity, WBTC was sent to the specified address, and the smart contract used the previously granted approval.

In traditional finance, there is usually an intermediary between a person and the final execution of a payment. A bank can limit the amount, stop a suspicious transfer, or request additional confirmation. In cryptocurrencies, the owner of the private key can independently move millions. But along with the intermediary, part of the protection from one's own actions disappears.

Even a test transaction does not guarantee safety. Wintermute conducted trial transfers, a victim of address poisoning trusted the wallet's history, and an Aave user confirmed the warning about critical slippage. Bitcoin, DeFi tokens, or stablecoins follow the same logic in this regard: the owner's signature is crucial.

Large operations require several independent checks.

• Verify the address completely, not just the first and last characters.
• Choose the correct network before sending funds.
• Assess the expected output amount before confirming the swap.
• Check liquidity, especially for large exchanges.
• Regularly revoke unnecessary smart contract permissions.
• Use hardware wallets for large amounts.
• Enable two-factor authentication where available.
• Understand basic phishing and social engineering schemes to avoid trusting the interface automatically.

Before signing, check not only the amount but also the address, network, exchange route, liquidity, and permissions: in the blockchain, these parameters become the final order for the network.

The main advantage of self-custody remains its primary risk. No one can manage assets without the owner's consent. But if the owner themselves signed a wrong transaction, often there is no one to stop it.

Full control over cryptocurrency means not only freedom from intermediaries. It also means the possibility of losing money without intermediaries --- with one erroneous signature.