Part Three — Doors

Anchor tracks: Cryptocurrency, Buy The Floor

The reader's question: how do I get in and out?

1. Exchanges — what they are and what they aren't

An exchange is a business where you swap ordinary money for crypto and back again. It is where nearly everyone starts, and there is nothing wrong with that.

The thing worth understanding on day one is what you actually have while your funds sit there.

A centralised exchange — a CEX — holds the keys. It runs an internal database of who is owed what, and most of the trading you do never touches a blockchain at all; it adjusts numbers in that database. The chain only becomes involved when you withdraw.

So a balance on an exchange is an IOU. It is a claim against a company, not coins you hold.

The interface makes this hard to feel. It looks like online banking, it has a login and a password reset and a support form, and it says you own 0.4 ETH. But there is no deposit insurance behind it, and the resemblance to a bank is a design choice rather than a legal reality.

Track 5 says it more directly than this chapter can: you'll give your crypto away to strangers. That is the accurate description of a deposit.

2. Counterparty risk

Counterparty risk is the risk that the party holding your money fails, freezes, or absconds.

Here is the fact that ought to reframe this whole subject:

Every major collapse in this industry was a company failing, not a blockchain failing.

Mt. Gox in 2014. Celsius, Voyager, and Three Arrows in 2022. FTX in 2022, which was among the largest and most reputable-seeming venues in the field, with celebrity endorsements and a stadium named after it. In each case the chains kept producing blocks the entire time, exactly as designed. The people who lost money had handed it to a business.

This is worth naming because the public story of crypto risk is about volatile prices and shadowy hackers, and the actual dominant loss mechanism has been ordinary corporate failure — sometimes fraud, sometimes incompetence, always with a familiar-looking website up until the week it stopped.

The phrase the culture uses is not your keys, not your coins. It is not a slogan. It is a description of the legal and technical reality.

What to do about it, proportionately: exchanges are genuinely useful for buying, selling, and converting. Use them for that. Decide a maximum you are willing to have sitting on any platform at any time, and move the rest to a wallet you control. The right maximum for most people is "the amount I am actively trading with," not "everything."

3. KYC

KYC means Know Your Customer. Almost any exchange dealing in ordinary money will require it: photo identification, proof of address, sometimes a selfie or a video check.

This is not optional and it is not a scam. It is anti-money-laundering law, and it applies to banks in the same way.

What it means practically:

• Your identity is linked to your withdrawal addresses. The exchange knows which chain addresses you sent funds to, and that record persists.
• The data is held by the exchange, which makes it a target. Exchange customer databases have leaked, and those leaks have been used for targeted phishing and, in a small number of cases, for physical targeting.
• Verification takes time. Doing it when you are calm rather than when you urgently need to sell is simply practical.

Use a strong unique password and app-based two-factor authentication on any account with your identity documents attached. Not SMS — see Part Four.

4. Fees, gas, and congestion

Every transaction on a chain costs a fee, called gas on Ethereum and quoted in gwei.

The fee is not a fixed price. It is an auction for limited space in the next block. Offer more, get included sooner; offer too little, wait or fail.

Two consequences catch people out.

A fee can exceed the amount you are moving. Sending twenty dollars of a token can genuinely cost thirty dollars during a busy period. There is nothing to appeal to; the network does not know or care that the fee is absurd relative to your transfer.

Congestion arrives exactly when you want to act. Fees spike during crashes and popular launches — the two moments when everyone tries to transact at once. If your plan is "I'll move my funds if things go wrong," you have scheduled that move for the most expensive and least reliable moment available.

What to do:

• Check the fee in your own currency before confirming. Every time.
• For anything non-urgent, wait. Fees fall when activity does, and a fee tracker costs nothing.
• Keep a small amount of the chain's native coin in every wallet. People routinely get stuck holding tokens they cannot move because they have no ETH left to pay the fee with. The tokens are not lost; they are just immobile until you send more ETH in.
• Rehearse the transfer you might need in an emergency, now, with a small amount, while the network is quiet.

5. Layer 2s

A Layer 2 is a separate, faster, cheaper network that batches its activity back down to the main chain, inheriting the main chain's security. The most common design is a rollup, which rolls many transactions into a single record posted below.

For everyday amounts this is the difference between usable and not. Fees are frequently a small fraction of the main chain's.

The tradeoffs are real and worth knowing before you use one:

• Addresses look identical across layers. Sending to the right address on the wrong network is a common and often unrecoverable mistake. Always confirm which network the recipient expects.
• Withdrawals can be delayed. Some rollups hold withdrawals to the main chain for days by design. That is a security feature, and it is also a surprise if you did not read about it first.
• You are trusting more moving parts. The security argument is strong but not identical to the main chain's.

Before your first Layer 2 transfer: confirm the network, send a small test amount, and look up the withdrawal period.

6. Getting out

The off-ramp is the part people plan least and need most.

Getting money out generally means selling on an exchange and withdrawing to a bank account — which means an account that has passed KYC, a bank that will accept the transfer, and a record of what you paid.

Three things to sort out early, while nothing is urgent:

Have a working route before you need one. Verify the account, link the bank, and do one small withdrawal end to end. Discovering that your bank rejects crypto-related transfers, or that verification takes eleven days, is much better as a dull Tuesday than as an emergency.

Know your tax position. In most countries a disposal is a taxable event, and that includes swapping one token for another — not only cashing out. This is why cost basis matters, and why the advice in Part One was to record the date, the amount, and the value in your own currency from your very first purchase. People trade for a year, discover they cannot prove what anything cost, and are taxed on the full proceeds rather than the gain.

Understand that limits exist. Withdrawal limits, daily caps, and holds after adding a new bank account are all normal, and all of them are discovered at the worst time by people who never tested the route.

Written outcome

You can move a small amount on and off an exchange to your own wallet, and you know what you are trusting at each step.

Do it once with an amount you would not mind losing. The rehearsal is the lesson.

Next: Part Four comes before the tutorial chapter, deliberately. You learn how to lose money before you learn how to move more of it.