How markets actually work

Every market does the same four jobs: match buyers to sellers, discover a price, provide liquidity, and settle. What differs is who performs each job and what they charge. That difference explains most of what feels arbitrary.

Every way of making money runs through a market. Stocks, houses, advertising, labour, freelance work, crypto — all of them are places where someone with a thing meets someone with money.

They look nothing like each other. Selling shares takes a second; selling a house takes months. An advertising slot is priced in an auction that finishes before a page loads; a salary is negotiated once a year, awkwardly, with almost no information.

Underneath, they are doing the same four jobs. The differences are entirely about who performs each job, and what they take for it — and that turns out to explain most of what feels arbitrary or unfair when you participate in one.

The four jobs

1. Matching. Someone who wants to buy has to find someone who wants to sell. This sounds trivial and is the hardest problem in most markets. Employers and workers, landlords and tenants, advertisers and audiences — matching is why intermediaries exist and how most of them are paid.

2. Price discovery. The price has to come from somewhere. In some markets it is continuous and public, updating every millisecond in view of everyone. In others it is a negotiation between two parties, in private, where neither can see what anyone else paid.

3. Liquidity. Can you get out? Some markets guarantee a counterparty at a published price at any moment. Others offer no guarantee at all: your house is worth what someone will pay, when someone appears. This is the property that varies most, and the one people most often assume they have.

4. Settlement. Ownership changes hands, money moves, and someone guarantees neither party is cheated. Boring, invisible when it works, and expensive — most of what an estate agent, exchange or escrow service charges is for this.

The same four jobs, six ways

Read the table by column and things jump out. Liquidity is high in exactly one row and manufactured there — it does not occur naturally. Price discovery is public in two rows and private in the rest, which means in most markets you are negotiating without knowing what anyone else paid. And there is always somebody in the last column.

Why this is the useful lens

Three things follow, and they matter more than any individual market’s details.

The cost is often invisible by design. In markets with continuous pricing, the fee is embedded in the gap between the buy and sell price rather than charged separately. You pay it on every transaction without seeing a line item. “Free” trading is free of commissions, not free.

Liquidity is a service, not a property. Your ability to sell instantly exists because someone is willing to take the other side, and they are willing because they are paid. When conditions get bad, they widen their prices or stand back — which means liquidity thins exactly when you most want it. Anything that depends on being able to exit quickly should be sized on that assumption.

Where price discovery is private, information is the whole game. In housing, labour and freelance markets, you are negotiating against someone who has done this many times and knows the distribution of outcomes, while you have done it a handful of times. That asymmetry is not incidental. It is the market’s structure, and the fix is to get the information rather than to negotiate harder.

What this series does

One post per market, each answering the same questions: who is on the other side, how the price is arrived at, whether you can get out, and who is paid along the way.

• How is there always a buyer? — the stock market, market makers, and the spread you pay without seeing
• How the advertising auction works — the machinery behind blogging, YouTube and every ad-funded thing
• How house prices are actually set — a market with no market maker
• How your wage is actually set — the least efficient market most people participate in
• How crypto markets actually work — where a formula replaced the market maker
• The market that sets the price of everything — bonds, and why your mortgage rate starts there
• How private markets work — and why you cannot get in
• How freelance platforms actually work — reputation as collateral, held by someone else

The point is not to trade better. It is that every method of making money sits inside one of these, and the structure of the market determines a great deal about what is possible inside it — more than effort does, and more than most people realise when they choose what to spend years on.

If you have not read how money actually flows, that describes where the money comes from before it reaches any market. This describes what happens once it is there.