(plural materializations) 1  The conversion of something into a physical form. ( 2 physics) The conversion of energy into mass.
Market Order-- to sell Hutchison: sell Hutchison now at whatever prevailing market price. Usually one will get the stock at the ask price of the moment when the order reaches the exchange. Sometimes, one gets a series of partial trades (partially filled orders) at different prices, the shares of which add up to 2000.
You can also think of them as the market price of a stock--bid being the market price if you are selling at the market and ask being the price if you are buying at the market. It is a fee that the market maker pockets as payment for keeping the market liquid.