Mid-price

Mid-price or Middle Rate
The price half-way between the two prices, or the average of both buying and selling prices offered by the market makers.

Mid-price
The mid-price is halfway between the bid and the ask (offer) prices. For example, if the bid is 1.4426 and the ask is 1.4430, the mid-price is 1.4428.
Module ...

Mid Price: Mid-price is the midway point between the bid and the ask price.

where MP(t) is the mid-price of the latest period, and n is the number of periods considered.
Then, the standard deviation can be calculated as follows:
Std.Dev. = Sqrt( ( (CP(t))^2 + (CP(t-1))^2 + ... + (CP(t-n+1))^2 ) / n ) ...

Mid-Price or Middle Rate : The price half-way between the two prices, or ...
Milliard : European term for 1,000 million.
Million : The number that is represented as a one followed by 6 zeros.

This is the last automatic trade or uncrossing price for a security in SETS or the mid-price for a security in SEAQ, SEATS, AIM or an international security (that is securities in EULQ, LSTD, NLLD or OINT market segment.

See also: Trading, Margin, Premium, Order, Market Order