Kraken is an exchange: it facilitates trades and manages funds held in client accounts. A useful starting point is to follow a purchase from the quoted price to the account balance and then to a withdrawal into your own wallet. Each step has different conditions.
Imagine buying bitcoin on Kraken and seeing a BTC balance appear in your account. The exchange records your entitlement to that amount, but it still manages the private keys that authorize bitcoin transfers. Kraken Exchange uses company wallets; your account password does not give you their keys. Withdrawing to a wallet whose keys you control puts subsequent transfers in your hands. The same brand also offers Kraken Wallet, a separate product for managing your own keys. That is a different product, not a feature of every exchange account. [1]
Products also differ in which company you contract with. For the European Economic Area, Kraken lists Payward Ireland Limited for e-money and payment services, Payward Europe Solutions Limited for cryptoasset services, and Payward Global Solutions Limited for the trading platform. Here, e-money means monetary value held with a provider, not bitcoin. For a particular service, it therefore helps to identify the provider, its terms and its availability in your country of residence. One company's licence does not automatically cover every group product or every country. [2]
Kraken Pro brings buyers' and sellers' orders together. A market order says: buy now at the available prices. The last price on screen is therefore not a promise of your purchase price. A buy limit order instead sets the highest price you will accept; it may fill only partly or not at all if suitable offers are unavailable. This also explains maker and taker. A maker adds an offer waiting for a counterparty; a taker uses an offer already available. Even a limit order can be a taker if it matches immediately. The word “limit” alone therefore does not tell you the trading fee. [3]
With Instant Buy, a simple purchase can involve a trading fee, a payment-method fee and a spread: the difference between the quoted rate and the corresponding market price. Some of the cost can thus be built into the rate itself. Kraken Pro uses a different maker/taker schedule, depending on the product and applicable account tier. An offer of zero trading fees does not by itself remove spread, payment costs or withdrawal costs. Comparing what you pay in total with how much bitcoin you finally receive is more useful than looking at one prominent advertised rate. Check the current terms of the transaction before confirming it. [4]
Bitcoin can appear in your account after a purchase without being available for withdrawal yet. Kraken describes possible 72-hour withdrawal holds on certain card or digital payments, and seven days for purchases through ACH Plaid, one way to pay from a US bank account. For these purchases, the restriction concerns the equivalent amount: it need not lock the entire balance, and trading can continue. If you plan to transfer to your own wallet, check the withdrawable amount rather than just the total balance. These periods are examples; the actual restriction depends on the payment method and account status. [5]
Refunds can bring another surprise. When you withdraw bitcoin, Kraken sends it from an operational wallet, not from the deposit address assigned to your account. The recipient should therefore not automatically return bitcoin to the address it came from. That is not your personal return address, and Kraken warns that funds returned this way may be unrecoverable. To receive funds on the exchange, use the current details on its deposit page. A deposit address, the sending address of a withdrawal and your own wallet address serve different purposes here. [1]
Leaving funds on an exchange raises the question of whether it actually has them. Kraken publishes Proof of Reserves, a check at a particular point in time involving an independent accounting professional. Records of the included client balances are combined in a Merkle tree, a structure that lets you verify your record's inclusion without publishing everybody else's balances. The total is compared with corresponding assets the exchange demonstrates it controls. This is useful but limited evidence: it does not by itself rule out hidden claims against assets, assets borrowed for the check, copied private keys or a later loss. Read the date, scope and methodology together. An older check does not establish today's position. [6]
Protecting ordinary money in an account is a different question from bitcoin reserves. Kraken says Payward Ireland Limited separates European Economic Area clients' funds from its other money through safeguarding. The purpose is to reserve those funds for clients' e-money and payments. The company is not a bank, however, and this e-money is not covered by Ireland's Deposit Guarantee Scheme. If the company fails, claims are generally met from the safeguarded funds; returning money can take time, and administrators' costs may reduce the amount received. Safeguarding is therefore not bank deposit insurance, nor does it imply bitcoin insurance or risk-free custody. [7]
For the clearest picture, read this entry together with Custodial Exchange, Self-custody, Coinbase, Proof of reserves. The reverse links also lead from Coinbase, Bitstamp.