Bid Extensions
Some auctions use bid extensions to give bidders time to respond to a bid near closing. For example, a sale might extend a lot when a bid arrives during its final five minutes. The trigger window and added time are set by that auction; check its terms or the lot page for the actual rules.
An extension can occur more than once if qualifying bids continue. Watch the lot's updated countdown and confirm whether you are still the leading bidder. The original scheduled close time may no longer be the final end time.