RE: mid price9 Jan 2019 14:55
bit more on markets, I know not everyone will be interested but this is via the London Stock Exchange so should be accurate, will add to wiki88;
"There are two main types of trading mechanisms:
• Order driven markets
• Quote driven markets
In an order driven market, buyers and sellers of assets are able to place orders for assets they wish to purchase or sell. They can list at market price, which executes a market order instantaneously at the best available price.
In a quote driven market, continuous prices or “quotes” are provided to buyers and sellers. These prices are provided by market makers, which mean these types of systems are better suited for dealer or OTC markets.
You can gain a good knowledge on order driven and quote driven markets by referring this URL : https://www.investopedia.com/ask/answers/06/quoteorderdrivenmarket.asp
Regarding what is ‘off-book’ : An ‘off-book’ trade refers to a stock trade that is executed away from the exchange, via the OTC market.
Usually, a trade price is agreed between two parties and then one of the two trade participants will report both sides of the trade to the market in order to bring the execution ‘on exchange’. This reporting process can be delayed up to a specified time, according to the exchange’s parameters, and doesn’t have to be immediate."