Economics becomes a science · 1770s–1920s
1870s
The specialist's book
On the New York Stock Exchange, one trader per stock keeps a book of orders waiting at each price.
From the 1870s, New York Stock Exchange specialists stood at one post and handled one stock. They kept a book of customers' orders to buy or sell at set prices, including orders to sell if the price fell to a level, and filled orders to buy or sell at once from it.
They were expected to trade themselves to keep the market orderly when buyers or sellers were scarce.
💡 Why it made sense then
As trading grew, someone had to match orders that arrived at different times and keep a price available.
Ideas it gave us
- 🧾 Order book
An order book is the live list of buy and sell orders waiting at each price for a stock.
- 🧾 Limit order
A limit order buys or sells only at a set price or better, so you control the price but it may never fill.
- 🧾 Market order
A market order buys or sells straight away at the best price available, trading certainty of filling for certainty of price.
- 🧾 Stop-loss order
A stop-loss order sells automatically once a stock falls to a set price, to cap how much you can lose.
- 🧾 Liquidity
Liquidity is how easily something can be bought or sold quickly without moving its price much.
Practise with $10,000 in play money
Free. No real money involved.