According to CoinMeta, there is a tax aspect that users who have lost their crypto assets due to hacker attacks (such as cold wallets), dead wallets, or exchange crashes should be aware of. Due to firmware vulnerabilities in cold wallet incidents, attackers were able to obtain the mnemonic phrases generated by some devices through brute-force cracking, resulting in the wallets being emptied. Although the losses cannot be recovered, users can claim capital losses, provided they can prove that they owned these assets and that they are irrecoverable. Such losses can offset capital gains, and the remaining amount can be carried forward to future years. For such thefts, evidence is crucial, including purchase records, wallet addresses, records of funds flowing out of the blockchain, and police reports. The more substantial the evidence, the smoother the claim process will be. It is important to note that in the case of exchange crashes (such as FTX, Celsius), claims cannot be made on the day of management; losses are confirmed at the end of the management period, based on the actual amount recovered. Many people attempt to file claims too early. Additionally, worthless tokens that are still held (such as those with a 99% decline in value) are not considered losses; a loss can only be recognized when they are sold. For victims of cold wallet incidents, it is recommended to address new wallet and security issues first, and tax matters can be dealt with later.