BID Price is the highest price a buyer of a security is willing to pay for a unit of the security at a particular time. These are the prices under the BID Column in green color. 


Example:


The highest bidder is willing to buy 5,500 shares of the stock at the price of 38.85 per share.  There are currently 5 bidders buying at the same price of 38.85 with a total of 5,500 shares.