Crypto custody refers to who holds the private keys that control access to your assets. If you hold your own keys (self-custody), only you can initiate transactions. If an exchange or institution holds your keys, they can transact on your behalf and you depend on their solvency and honesty. The FTX collapse in November 2022, which resulted in roughly $8 billion in customer losses, is the clearest recent example of what happens when custodial risk materializes.
How crypto custody works
Self-custody means generating and storing your own private keys, typically through a hardware wallet (Ledger, Trezor) or a software wallet (MetaMask, Rabby, Phantom). The wallet generates a 12 or 24-word seed phrase that must be stored securely offline. Anyone with access to the seed phrase has full control of the wallet; there is no recovery mechanism if it is lost.
Exchange custody (custodial accounts on Coinbase, Binance, Kraken) means the exchange holds keys on your behalf and credits your account balance. You trade faster and can recover account access if you forget your password. The trade-off is that your assets are an unsecured creditor claim against the exchange, not property you hold independently. Institutional custody (Coinbase Custody, Anchorage, Fireblocks) uses multi-signature or MPC arrangements and regulatory-grade security for large holdings, typically with insurance coverage.
What this means for traders
Active traders on centralized exchanges carry custodial risk as an ongoing exposure. Standard risk management practice: keep only the amount you are actively trading on any single exchange and hold larger positions in self-custody. Hot wallets (internet-connected software wallets) are convenient but more exposed to malware and phishing. Cold wallets (offline hardware wallets) are more secure but less convenient for frequent trading.
A common approach: active trading margin on one or two exchanges, medium-term and long-term holdings on a hardware wallet. The goal is not zero exchange exposure (which would prevent trading) but sizing that exposure so a single exchange failure does not materially affect your total position. See: crypto risk management and crypto wallet security.
A concrete example
In November 2022, FTX halted withdrawals and filed for bankruptcy. Customers with assets on FTX lost immediate access and received cents on the dollar in the years-long bankruptcy proceedings. Customers who had moved assets to self-custody wallets before the halt were unaffected. The total customer shortfall was approximately $8 billion. Customers who used FTX as long-term storage lost the most; those who kept only active trading margin there had far less exposure.
Frequently asked questions
What is a multi-signature wallet?
A multi-sig wallet requires multiple private keys to authorize a transaction: for instance, 2 out of 3 designated keys must sign. This is used by institutions and DAOs to prevent single points of failure. If one key is compromised, transactions cannot be executed without the additional required keys. Gnosis Safe is the most widely used multi-sig wallet in DeFi.
What is MPC custody?
Multi-party computation (MPC) custody splits a private key into multiple fragments held by different parties. No single party holds the complete key; reconstructing it requires combining fragments. This is how institutional custodians like Fireblocks and Copper operate. It provides security without the coordination overhead of traditional multi-sig and removes single points of failure.
How do you securely store a hardware wallet seed phrase?
Store the seed phrase on paper or metal (not digitally) in a physically secure location, separate from the hardware wallet itself. Do not photograph it, type it into any device, or store it in cloud services. Some people split the phrase across two locations, each half useless alone. The seed phrase is the wallet; wherever it is compromised is where your assets are lost.
