What a stock exchange actually does
What you'll learn
The four jobs every exchange performs, and the one-sentence version of each.
Strip away the regulation, the co-location halls, and the ticker tape, and an exchange is a machine with four jobs:
- Take orders in. Accept instructions to buy or sell — safely, fairly, and only from people allowed to trade.
- Match them. Pair willing buyers with willing sellers according to published, deterministic rules.
- Tell everyone what happened. Broadcast prices, quotes, and trades to the entire market at once — market data is the exchange's most consumed product.
- Make the trade real. After the match, move the money and the shares: clearing and settlement.
flowchart LR
T["Traders"] -- orders --> IN["1 · Order intake"]
IN --> M["2 · Matching"]
M -- prices and trades --> MD["3 · Market data"]
MD -- broadcast --> T
M -- executed trades --> PT["4 · Clearing and settlement"]
PT -- cash and shares move --> T
Notice the loop: market data feeds back into traders' decisions, which produce more orders. This feedback loop is why latency fairness matters — if some participants see prices before others, they can systematically pick off the slow. It is also why market data and matching must never disagree.
Key ideas
- An exchange = intake + matching + market data + post-trade.
- Market data is a product, not a byproduct — and it must be released fairly.