Hot Wallet

A hot wallet is any cryptocurrency wallet whose private keys are held on a device that is connected to the internet. That covers the account you hold on an exchange, the wallet app on your phone, a browser extension, and the balance shown inside almost any service that lets you send crypto with a tap. The word ‘hot’ refers only to that connection — not to how much the wallet holds or how new it is.

The connection is the whole trade-off. Because the keys are reachable by software, a hot wallet can sign a transaction the moment you ask it to, which is what makes it usable for everyday payments and for selling quickly when a rate is good. The same reachability is what an attacker needs: malware on the device, a convincing phishing page, a compromised browser extension, or in the case of an exchange account, a breach on the company’s side rather than yours.

A cold wallet is the opposite arrangement. Its keys never touch an internet-connected machine, so a remote attacker has nothing to reach, and the cost is that spending from it takes deliberate effort. Neither is the ‘right’ one. They are tools for different jobs, and most people who hold crypto for any length of time end up using both.

The practical rule that follows is a familiar one: treat a hot wallet the way you treat the cash in your pocket and a cold wallet the way you treat what you do not carry around. Keep in the hot wallet what you expect to spend or trade soon, and move the rest to storage that is offline. There is no threshold that applies to everyone — the sensible amount is the one you could lose without it changing anything important.

Two details matter more than they look. First, a wallet held on an exchange is a hot wallet where the keys are not yours at all; you hold a claim on the company, not the coins, and its security is theirs to get right. Second, ‘hot’ is not a synonym for careless. A phone wallet with a strong passcode, an up-to-date operating system and a recovery phrase written on paper and stored somewhere safe is a reasonable place to keep spending money.