Main to remember
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A misunderstanding of the costs units led to an accidental too much in the value of more than $ 60,000 during a replaced transaction.
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The user confused SAT / VB (fresh by byte) with a total Satoshis, leading to an extreme excess.
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RBF replaces a transaction with a more frequent version, while CPFP adds a new transaction to increase the original; Everyone has different use cases and risks.
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Use confidence portfolios, check the fresh units and let the portfolio Suggest optimal costs. Avoid panic, stay up to date and always check the transactions before hitting “send”.
Around 12:30 am UTC on April 8, 2025, a Bitcoin user tried to accelerate a pending transaction using replacement-by-fee (RBF). But instead of a modest bump, their portfolio in error spent 0.75 Bitcoin (BTC), around $ 60,000 at $ 70,000, only in costs.
How does something like it happen? And more importantly, how can you make sure that it does not happen to you?
Let’s decompose it.
Why did a Bitcoin user end up paying $ 60,000 in costs?
The user wanted to send 0.48 BTC (about $ 37,770 at that time) using the Bitcoin RBF function. This feature allows you to return a transaction with higher costs if the original is stuck in the MECPOOL (the waiting area of unconfirmed transactions). In this case, things went wrong, very badly.
Chronology:
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First transaction: Sent with standard costs, not high enough to confirm quickly.
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First attempt by RBF: Doubled the costs and modified the address of the recipient (outing).
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Second attempt by RBF: Addition of a large unit (UTXO) transaction exit, approximately 0.75 BTC, but forgot to redirect the change to their own address.
The result? This 0.75 BTC was treated as costs and sent to minors.
Anmol Jain, vice-president of surveys of the Crypto AMLBOT Legal Medicine Society, told Cointtelegraph that the user had probably started with “default or conservative” transaction costs, which is nothing unusual. Then came the error: confuse the way the costs were measured.
Many Bitcoin portfolios allow you to set costs in two ways:
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Total costs in Satoshis (The smallest Bitcoin unit, like cents with a dollar)
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Fresh by virtual byte (SAT / VB), which measures how heavy “transaction is in terms of data
Here is where things went wrong, according to Jain:
“The system reads it as total costs of 30 SATS, which is far too low, so the types of user 305000 thinking that this means 30.5 SAT / VB, and the wallet actually applies 305,000 SATS / VB, which is crazy.”
In simple terms, the user may have seen a warning that their costs, only 30 SAT in total, were too low for the transaction to be treated quickly. Thus, trying to repair it, they could have type 305,000, thinking that it meant “30.5 SAT per byte”.
But instead of adjusting the costs moderately, the portfolio took this at 305,000 SAT per byte, monstrous costs which have exceeded the standard and led to a loss of more than $ 60,000.
Why it matters
This underlines how the minor confusion between the costs units can cause major losses, especially when entering the numbers of numbers quickly or the use of advanced wallet parameters without fully understanding them.
So, if you adjust Bitcoin costs, turn back the unit you define. Whether it is “total SAT” or “Sats per byte” makes a world of difference, as evidenced by this expensive error.
Did you know? In September 2023, a user paid costs of $ 500,000 For a single BTC transaction. It turned out to be a paxos error, a cryptographic infrastructure company.
Replace by costs (RBF): What is it?
Bitcoin transactions are not final until they are added to a block. If a transaction is blocked, you can use RBF to return it with higher costs to encourage minors to recover it more quickly.
It was initially proposed by the creator of Bitcoin, Satoshi Nakamoto, then formalized later as “Opt-in RBF” by the developer Peter Todd, according to the Bitgo Developer Portal.
How it works:
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You activate RBF when sending the original transaction.
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If the transaction remains unconfirmed, you can create a replacement with higher costs.
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Minors will probably choose the more frequent version because they are financially encouraged to do so.
But here is the capture: if you spoil entries or exits, in particular the change address, it can cost you dearly.
In particular, RBF differs from the Child-Paty-Pour-Parent (CPFP) in that RBF replaces the original unconfirmed transaction with a higher 1-fee version, and only the sender can launch it. On the other hand, CPFP adds a transaction of children at high end to increase the confirmation of the parent and can be launched by the sender or the receiver.
Why do Bitcoin transaction costs increase so high?
There are a few theories behind what caused the absurd costs in this case:
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Confusion on expense units: The fees probably increased due to a misunderstanding of the costs units. Instead of fixing a reasonable price per byte, the user may have accidentally seized a great absolute value, which means that the wallet applies excessively high costs.
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Automation went wrong: If the portfolio uses automated scripts or has bugs in the way it deals with RBF, user’s inputs can be ill -read or, worse, executed without appropriate warnings.
Why RBF is controversial
The RBF functionality has triggered years of debate within the cryptographic community. Although it is useful to repair stuck transactions, criticisms like Mike Hearn (former Bitcoin developer) have argued on the medium: He: He: He: He:
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Allows double expenditure attacks, in particular for merchant transactions in person.
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Encourages collusion by minor fraud.
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Add complexity, making user errors more likely.
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Soft the purpose, because unconfirmed transactions can be replaced.
To solve this problem, Bitcoin Cash (BCH), for example, deleted the RBF support and says that the unconfirmed transactions are final. However, due to the functioning of mempools, similar RBF type replacements can still occur, even on BCH.
Did you know? In November 2023, a transaction of 139 BTC (worth millions) included fees of $ 3.1 million.
How to protect yourself from high Bitcoin transaction costs
You don’t need to fear RBF, but you have to respect it. Here are some tips to avoid becoming the next failure for viral costs:
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Choose a secure bitcoin wallet with transparent costs of costs: Choose renowned Bitcoin portfolios that display and clearly explain the types of costs.
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Understand Bitcoin costs units before sending: Learn the difference between SAT / VB (Satoshis by virtual byte) and total Satoshis to avoid accidental overpayments.
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Always check your transaction before confirming: Check the recipient’s address, the amount of costs and the modification address to ensure that no funds are wrongly used as a minor.
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Let the wallet suggest the costs, especially if you are new: Most portfolios offer recommendations for dynamic fees based on network congestion, so use them instead of manually grasping values.
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Test with a small Bitcoin transaction first: Send a low value test transaction to confirm that everything is defined correctly before sending a significant amount.
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Monitor Bitcoin network fees in real time: Use websites like Mempool.Space to check the current costs of costs and choose the best time to send your transaction.
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Avoid panicking on slow confirmations: Bitcoin transactions can take time. Wait before overthrow or replace transactions, unless you are sure that it is necessary.
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Stay informed of portfolio updates and bugs: Follow your portfolio provider for updates, as software bugs or interface changes can have an impact on how the costs are calculated or displayed.
If you jump the above precautions, you could pay hundreds, even thousands of dollars in unnecessary costs, without any way to recover the loss. Regarding Bitcoin, a small error can become an expensive lesson.
This article does not contain investment advice or recommendations. Each investment and negotiation movement involves risks and readers should conduct their own research when they make a decision.
