The transaction is designed to time out and disappear. The funds are never actually transferred.
No legitimate blockchain system allows permanently reversible or magically duplicated coins. Claims involving flash coin systems that can bypass confirmations or generate unlimited funds are technically impossible under real network consensus rules.
: Once miners add a block to the blockchain, the transaction cannot be changed or reversed. flash btc transaction core network 63 0 best download
of unconfirmed transactions in more detail
Searching for "Flash BTC Transaction (Core Network) 6.3.0" likely leads to fraudulent software The transaction is designed to time out and disappear
"The 'best download' is a myth. Just take official Core, set maxconnections=200 and use a fee of 100 sat/vByte. It's the same thing without the malware risk." –
The coins eventually return to the sender's wallet after a specific period. Claims involving flash coin systems that can bypass
: Some services allow you to pay a small fee to accelerate your transaction. One of the most well-known is ViaBTC's Transaction Accelerator. You'll need to enter your transaction ID and pay a small fee.
The software creates a valid transaction with a very low fee, then uses Replace-By-Fee (RBF) or a double-spend maneuver to broadcast a second transaction with a higher fee that sends the same coins back to the sender's own wallet. If a recipient accepts the first transaction with zero confirmations (0-conf), they lose their funds when the second transaction is mined instead.