Buying Bitcoin: Exchanges, Orders, Spreads, Fees and MiCA

What you will learn

• The difference between exchanges and broker-style apps
• How market and limit orders work
• How to calculate the full cost: spread, trading fee and withdrawal fee
• What MiCA is and how to check a provider's authorisation

Explanation

An exchange is a platform where buyers and sellers place orders in an order book, a list of open buy and sell orders. A broker-style app often shows one simple "buy" price; its cost may be built into that price.

The bid is the highest price a buyer currently offers. The ask is the lowest price a seller currently accepts. The spread is the difference: ask − bid. You buy at the ask and sell at the bid, so you lose the spread on a round trip.

• A market order buys immediately at the best available prices. It is fast, but in fast markets you may get a worse price than shown. This difference is called slippage.
• A limit order buys only at your price or better. You control the price, but the order may never be filled.

Costs to check: the trading fee (often a percentage), the spread, deposit fees, and the withdrawal fee to move coins to your own wallet. Some providers advertise "zero fees" but use a wider spread.

MiCA (Markets in Crypto-Assets Regulation, Regulation (EU) 2023/1114) is the EU's rulebook for crypto-asset service providers (CASPs). Its rules for stablecoins applied from 30 June 2024, and the rest from 30 December 2024. National transitional periods ended at the latest on 1 July 2026. Since then, firms offering crypto-asset services to EU clients need a MiCA authorisation. In Germany, the supervisor is BaFin (Federal Financial Supervisory Authority). The European Securities and Markets Authority (ESMA) keeps a register of authorised providers.

Before using any provider, check that the exact legal entity you contract with is in that register. Authorisation is not a guarantee against losses: crypto prices can still fall sharply, and MiCA does not protect your coins like a bank deposit guarantee.

Worked example

Hypothetical example: the full round-trip cost of a €1,000 purchase.

Assumptions (all hypothetical): mid price €50,000 per BTC; ask €50,100; bid €49,900; trading fee 0.5% on each trade; withdrawal fee 0.0001 BTC. No slippage; taxes excluded.

1. Trading fee on purchase: €1,000 × 0.005 = €5.00. Amount used to buy: €995.00.
2. BTC bought at the ask: €995 ÷ €50,100 = 0.019860 BTC (rounded).
3. After withdrawal fee: 0.019860 − 0.0001 = 0.019760 BTC.
4. Value at mid price: 0.019760 × €50,000 = €988.00.
5. If you sold immediately at the bid: 0.019760 × €49,900 = €986.02, minus 0.5% fee (€4.93) = €981.09.
6. Round-trip cost: €1,000 − €981.09 = €18.91, or about 1.89%.

So the price must rise about 1.9% just to break even in this example.

Common mistake

Practice activity

Hypothetical: you buy for €2,000. Ask €40,200, bid €39,800, trading fee 0.25% per trade, no withdrawal. (a) How much BTC do you get? (b) What do you receive if you sell immediately? (c) What is the round-trip cost in € and %?

Limitations: real spreads change all the time and market orders can slip further in fast markets.

Key takeaways

• You buy at the ask and sell at the bid; the spread is a real cost.
• Limit orders control price; market orders control speed but can slip.
• Compare total round-trip cost in euros, not just the advertised fee.
• Since 1 July 2026, check the ESMA register for MiCA authorisation; it does not remove market risk.

Next step

In the next lesson, you will learn how to size crypto positions so that volatility cannot ruin your plan.