What is the 'Ask Size'
The ask size is the amount of a security that a market maker is offering to sell at the ask price. The higher the ask size, the more supply there is that people want to sell. When a buyer seeks to purchase a security, he or she can accept the ask price and buy up to the ask size amount at that price. If the buyer wishes to acquire more of the security over the current ask size, he or she may have to pay a slightly higher price to the next available seller.
BREAKING DOWN 'Ask Size'
Market makers are the ones who offer to buy and sell securities. The market maker must state the price it is asking for a given security (the ask price) and the amount it is willing to sell at that price (the ask size). Also, the market maker must state the price at which it is willing to buy the security (the bid price) and the amount of securities it is willing to buy (the bid size). When a customer order comes to the exchange, the order is filled by the market marker with the lowest ask price (for buy orders) or the highest bid price (for sell orders).