In the Agora, in order to make an exchange of shares of a project, there must be existing offers from the shareholders.
A bid, therefore is the interest to buy a published offer at a selected price. Once the bid is placed the seller must decide, whether he waits for a higher bid, rejects it or accepts it during the bidding period selected.
Bids can be classified under three states: active, sold and not sold.
An active bid is that one where the user is pending the confirmation of sale from the seller. This could be due to several factors, like that the seller is still awaiting the reception of more bids or for the offering period to finish to make a decision.
A lost bid is that one where the user was not able to buy the number of shares desired. This could be due to several factors, like the non conformism of the seller with your bid, that higher bids where made or that the formalization period for signature and payment processing the bid expired.
For winning bids the buyer must formalize the sale, to transfer share ownership through a signature and payment process.