How the exchange works

Market makers and home brokers

3 min

Two more players complete the picture of how a trade reaches the exchange: the home broker that you use, and the market maker that helps keep prices fluid.

The home broker

A home broker is the online trading platform your brokerage gives you — the screen (web or app) where you see quotes, view the order book and send orders. You never connect to the exchange directly; your broker is the licensed intermediary that routes your order to B3 (or the US exchange) and brings back the confirmation.

When choosing a broker, the things that matter most for stocks are:

  • Costs — brokerage fees per trade and any custody or platform fees.
  • Reliability — does the platform stay up during busy market opens?
  • Access — which markets it offers (B3 only, or US stocks too).
  • Tools — a clear order book, charts and order types.

The market maker

A market maker is a firm that continuously posts both a buy and a sell price for a security, standing ready to trade either side. By always being there, it provides liquidity — you can trade even when no other ordinary investor happens to be on the opposite side at that instant.

Market makers are especially valuable for less-liquid stocks, options and some ETFs, where natural buyers and sellers are scarce. They earn their keep from the spread between their buy and sell quotes.

Putting it together

Your click in the home broker becomes an order, the order joins the exchange's order book, a counterparty (sometimes a market maker) takes the other side, the clearing house guarantees it, and custody records the new ownership at D+2. That full chain runs in seconds — and now you know each link.

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Risk disclaimer

This content is for educational and informational purposes only and is not investment, financial, tax or legal advice. Trading and investing carry risk, including the possible loss of capital. Any performance shown by third-party tools is hypothetical and not a promise of future results. Do your own research and consider professional advice before making any decision.