Cold Wallet vs Hot Wallet vs Exchange Custody: Who Holds the Private Keys, the Risks of Each, and How to Split Your Crypto

There are three common places to keep crypto: in an exchange account (exchange custody), in a wallet app on your phone or browser (a hot wallet), or on a hardware wallet that stays offline (a cold wallet). The difference between cold wallets, hot wallets and exchange custody ultimately comes down to who holds the private key, and whether that key is connected to the internet.

The short version: none of them is completely safe; each protects against different risks. With exchange custody, the risk is something going wrong at the exchange: if it collapses, your assets become a claim that can take years to pay out. With a hot wallet, the risk is phishing websites and approval scams. With a cold wallet, the risks are losing or leaking your recovery phrase, buying a tampered device, and signing a transaction you did not read carefully. The practical approach is to split by purpose: what you plan to trade on an exchange, small everyday amounts in a hot wallet, and long-term holdings in a cold wallet. Exchanges split their own holdings the same way: Coinbase and Bitfinex both say publicly that their hot wallets hold only the small amount of assets needed to process withdrawals.

This article is a summary of information, not investment advice and not professional security advice. The cold and hot wallet practices of exchanges are their own statements, which outsiders generally cannot verify one by one. Data checked on 12 October 2026. Each exchange’s practices and the rules may change, so go by the sources.

Cold wallet vs hot wallet vs exchange custody in one table

The “device lost” and “recovery phrase lost” rows are based on Ledger’s explanation: coins are not stored on the device but recorded on the blockchain, and the device only holds the private key. A lost device can be restored on a new device with the recovery phrase, but without the matching recovery phrase, the assets really cannot be recovered (Ledger guide). Hot wallets are also restored with a recovery phrase.

Exchange withdrawal fees vary widely; on the same chain, one exchange can charge several times as much as another. See How to Choose a USDT Withdrawal Network.

The risks of each way of holding crypto

Exchange custody: hacks are usually covered, collapses take years

In Centralized Exchange Incident Timeline 2014 to 2026, I compiled 25 exchange incidents from 2014 to 2026. In 17 of the 20 hacks, users eventually got everything back, because the exchange covered the loss with a protection fund or its own money. But in none of the 4 collapses did users get their original coins back, and for the 3 with data, the median time from the incident to the first distribution was 1,562 days. Once an exchange enters bankruptcy proceedings, your balance becomes a “claim”, usually converted at coin prices on the date of the bankruptcy filing.

Another risk with exchanges is someone taking over your own account. You can reduce that with passkeys, withdrawal whitelists and anti-phishing codes; see Exchange Account Security Settings Compared. For the exchange’s own financial position, look at its proof of reserves; see How to Check Proof of Reserves.

Hot wallets: the most common losses come from approvals you click yourself

A hot wallet’s private key sits on an internet-connected device. Besides malware, the more common problem is being tricked into signing an approval. The “liquidity mining” scam described in a 2022 FBI alert gets victims to connect their wallet and accept permissions in a pop-up, after which the scammers can move an unlimited amount of assets out of the wallet; losses since January 2019 exceeded US$70 million. These scams do not need your private key. The approval you clicked is enough.

For common tactics and the warning signs, see Crypto Scam Playbooks in the Chinese-Speaking World. If you have already approved something suspicious, OKX’s advice is to revoke the approval, move the remaining assets to a new wallet, and stop using any recovery phrase that may have leaked.

Cold wallets: the key is offline, so the risk moves to the recovery phrase and the device itself

A cold wallet keeps the private key on a device that stays offline. Several companies make hardware wallets, such as Ledger. The private key never goes over the internet, but three risks remain:

• Losing the recovery phrase: the recovery phrase is a set of words that can restore all of your private keys. If both the device and the recovery phrase are gone, nobody can get them back for you. The best-known example is James Howells in the UK: a hard drive holding 7,500 BTC was thrown out with the rubbish in 2013, and on 9 January 2025 a UK court dismissed his lawsuit seeking to dig up the landfill (Fortune). Blockchain analytics firm Chainalysis estimated in 2017 that about 2.78 million to 3.79 million bitcoins, or 17% to 23% of the supply at the time, had already been lost (Fortune).
• A leaked recovery phrase or a tampered device: in October 2026, users who bought Ledger devices from the Southeast Asian reseller CryptoBilis had their assets stolen, and Ledger confirmed that one victim’s device contained an unauthorized hardware implant. For who to buy a cold wallet from and how to confirm it is brand new, see the Ledger theft incident. When I bought a new cold wallet in October 2026, I ordered it directly from Ledger.
• Signing a transaction you did not read carefully: a cold wallet protects the private key, but it will still sign any transaction you confirm on the device. In the Bybit case in the next section, the attack targeted the cold wallet’s signing process.

How exchanges themselves use cold and hot wallets

Exchanges also use both cold and hot wallets: most assets sit in offline cold wallets, and hot wallets hold only what is needed for day-to-day withdrawals. The table below lists the official statements I could find, plus two sets of rules with explicit percentages:

I found no official page from Binance or Bybit that publishes a cold and hot wallet split. The percentages in the table are the exchanges’ own statements, which outsiders cannot verify transaction by transaction. A high cold wallet percentage also does not mean an exchange has enough assets to repay its users; for that, look at the proof of reserves and the liabilities behind it.

A high percentage does not stop every attack either. On 21 February 2025, about US$1.46 billion was stolen from Bybit, and the target was an Ethereum multisig cold wallet. During a routine transfer from the cold wallet to a warm wallet, the attackers faked the transaction details shown in the multisig interface, so the signers actually signed a transaction that changed the wallet contract’s logic (Bybit incident timeline).

20 exchange hacks: hot wallets are hit most often, but the two biggest losses came through the signing process

I took the 20 hacks from Centralized Exchange Incident Timeline 2014 to 2026, reclassified them by which part of the setup was attacked, and added up the losses for each group. Amounts are the estimates at the time of each incident from the timeline table, using the midpoint where a range was given, and the officially announced US$1.46 billion for Bybit:

The table shows two things:

• By number of cases, hot wallets are hit most often: 16 of the 20. Hot wallets are online and have to process withdrawals in real time, so they are usually the easiest target, which is also why exchanges keep only small amounts in them.
• By amount, the 2 signing-process cases alone account for about 40%. In both, the problem was the signing process of a multisig wallet. No matter how offline the assets are, someone still has to sign to move them out, and the attackers went after that signing step.

I made this classification from the incident descriptions in the timeline. The amounts come from different sources and are only estimates at the time of each incident, and the sample includes only larger incidents with sources I could find, so treat the percentages as a rough guide, not complete statistics.

Applying this to your own cold wallet, this is my inference: a cold wallet solves the problem of private keys leaking, but reading what you sign is still up to you. When sending from a hardware wallet, go by the receiving address and amount shown on the device screen; if you cannot understand the transaction shown on the device, do not confirm it.

Splitting by purpose: what goes in a cold wallet, a hot wallet and on an exchange

The following are principles for splitting by purpose, not a ratio that suits everyone. How much to put where depends on how often you trade, how large your assets are, and how much loss you can bear.

1. Exchange: only what you plan to trade soon and can afford to lose. If something goes wrong at the exchange, you may wait a long time for assets held there, and if it collapses, you may not get your original coins back.
2. Hot wallet: treat it like a pocket wallet. Keep only small amounts for interacting with decentralized apps, do not use the same addresses as your long-term holdings, and regularly revoke approvals you no longer need.
3. Cold wallet: for long-term holdings. Write the recovery phrase only on paper or a metal plate; never photograph it or store it in the cloud. Anyone who asks you to enter your recovery phrase on a website, in an app or in a support chat is a scammer.
4. Once the amount is large enough that a failure anywhere would be more than you can bear, spread it out. Use different exchanges, different wallets and different recovery phrases, so a problem in one place does not affect the others. In the Ledger theft incident, one user deposited 7 million USDT three weeks after buying the device and lost all of it.

Exchanges’ practices are a useful reference: hot wallets hold only what day-to-day withdrawals need, the rest is kept offline, and transfers out require approval from several people. Individuals do not need to copy their percentages; what is worth borrowing is the approach: keep the small everyday amount somewhere convenient, and the rest somewhere less convenient but safer.

What to check before withdrawing from an exchange to a cold wallet

1. Finish the setup checks on the cold wallet first: the recovery phrase was generated by the device itself, the device passed the manufacturer’s authenticity check, and the first receiving address has no transaction history. For the steps, see the Ledger theft incident.
2. Confirm the receiving address: generate the receiving address in the cold wallet, go by the address shown on the device screen, and after pasting it into the exchange’s withdrawal page, check the first and last few characters.
3. Pick the right network: the network you choose on the exchange’s withdrawal page must be the same chain as that cold wallet address. For what happens if you pick the wrong network and how to recover funds, see USDT Sent on the Wrong Network?.
4. Send a small test amount first: send the rest once it arrives. I always send a small amount before moving a large one; I describe how in How to Choose a USDT Withdrawal Network.
5. Turn on the exchange’s withdrawal whitelist: add your cold wallet address to the whitelist, so that even if someone takes over your account later, it is harder for them to withdraw your assets to an unfamiliar address.

If your assets are mainly in US dollars or USDT, a cold wallet pays no interest. For the trade-offs against exchange earn products and US Treasuries, see Where to Park Idle USD and USDT. More security articles are on the crypto topic page.

FAQ

What is the difference between a cold wallet and a hot wallet?

Whether the private key is connected to the internet. A hot wallet keeps the private key on an internet-connected phone or computer. It is convenient, but it can be attacked by malware, phishing websites and approval scams. A cold wallet keeps the private key on a device that stays offline, and every transfer has to be confirmed on the device. That is more hassle, but the private key never goes over the internet. With both, you hold the private key yourself, unlike keeping coins on an exchange, where the exchange holds it.

Is it safer to keep coins on an exchange or in a cold wallet?

They protect against different risks. On an exchange, the exchange holds the private key. When an exchange is hacked it usually absorbs the loss itself, but if it collapses your assets become a bankruptcy claim; in the collapses this site has tracked, the median time from the incident to the first distribution was 1,562 days. In a cold wallet, an exchange collapse cannot touch you, but if your recovery phrase is lost or leaked, nobody can get it back for you.

If I lose my cold wallet, are the coins gone?

No, as long as you still have the recovery phrase. Ledger explains that coins are not stored on the device but on the blockchain; the device only holds the private key. If the device is lost, you can restore it on a new device with the recovery phrase. If both the recovery phrase and the device are gone, the assets cannot be recovered.

Do exchanges keep users' coins in cold wallets?

The large exchanges all say they do, but most do not publish the percentage. Coinbase wrote in its 2025 annual report that it generally keeps hot wallets to under 2% of custodied assets; Bitfinex says about 99.5% of user assets are in multisig cold wallets; OKX only says most assets are in offline cold wallets. Japanese rules require the portion managed in hot wallets to be no more than 5% of user assets, and Korea requires 80% or more to be in cold wallets.

Can assets in a cold wallet still be stolen?

Yes. A cold wallet protects the private key. It cannot stop a malicious transaction you sign yourself on the device, and it cannot protect you if your recovery phrase leaks or you buy a tampered device. When about US$1.46 billion was stolen from Bybit in 2025, the target was a multisig cold wallet, and the attackers altered the transaction details shown on the signing screen.

What is a hot wallet good for?

Small amounts you plan to use soon, such as funds for interacting with decentralized apps. It is online and you often have to approve permissions, so it is not suited to large amounts you plan to hold long term, and you should not use the same addresses you use for long-term holdings.