The Auction API features two queries that allow an authenticated user to retrieve auction bidding activity for a specific auction listing or bidding activity for a specific user over a specific date range.

The itemBiddingActivity query will return the most amount of information if the authenticated user making the query is the owner of that auction listing, a little less data for an authenticated user who has placed one or more bids on that auction item, and the least amount of data to an authenticated user who has not made any bids on that auction listing.

The userBiddingActivity query will return the most amount of information if the authenticated user making the query is retrieving their own bidding activity. Limited data is retrieved if the authenticated user if retrieving bidding activity on another eBay user.