Timed auctions allow bidders to place bids over a defined bidding window, with each lot closing according to scheduled platform rules rather than an auctioneer’s live call. They are one of the most widely used online auction structures because they combine convenience, transparency, and clear closing logic. This page explains how timed auctions work, including soft close, popcorn bidding, cascading lot closing, bid extensions, and maximum bidding behaviour.
At iRostrum, a timed auction is an auction where bidders can place bids over a defined bidding window and each lot closes according to scheduled lot close rules rather than an auctioneer’s live call.
This aligns closely with wider industry usage. The Saleroom describes timed auctions as online auctions where each lot can be bid on for a defined period and the highest bid at the end wins, provided the reserve is met. iRostrum should keep the definition practical and operational rather than abstract.
Each lot has its own closing time. In iRostrum, the first lot closes at the configured start close time and later lots generally follow at a set interval unless the instance uses different defaults.
This is one of the biggest terms users need help with because “timed auction” is not just about the auction starting and ending. It is also about the cadence of lot closures, whether lots close independently, and how extensions affect the order of sale.
At iRostrum, a soft close is a timed-auction closing mechanism where a bid placed shortly before a lot is due to close automatically extends the closing time of that lot. This is also commonly known as popcorn bidding.
The purpose is to prevent last-second sniping. If bidding activity occurs within the extension window, the system adds more time to the lot countdown so other bidders can respond. The process continues until no further bids are received within the extension window. This definition is stronger because it explains both the mechanism and the reason it exists.
Cascading lot closing is a timed-auction structure where lots close sequentially rather than all at once. Each lot has a scheduled closing time separated by a predefined gap from the previous lot.
This creates a clearer auction flow and allows bidders to focus on the lot currently approaching closing. The phrase is closely related to sequential lot closing. It is useful because it describes the auction schedule itself, not the bid-extension rule.
iRostrum supports both methods together, allowing auctioneers to combine sequential lot closing with soft-close bidding. Clients can configure whether extensions apply only to the active lot or also propagate to subsequent lots.
This is the important product-specific nuance. Auctioneers can choose between protecting only the current lot from sniping or shifting the remaining schedule forward so lot order and spacing are preserved. That flexibility should be called out clearly because it is operationally meaningful.
When a bid is placed within the extension window, only the lot receiving the bid is extended and other lots retain their scheduled closing times.
This behaviour prevents sniping on the active lot without changing the timing of later lots. It suits auctioneers who want later lots to remain fixed even if bidding becomes active on an earlier lot.
When enabled, if a lot is extended because of bidding activity, all subsequent lots are extended by the same amount.
This preserves the original lot closing order and keeps the configured gap between lots consistent. In practice, if bidding continues on an earlier lot, the remaining auction schedule shifts forward so later lots still close in the intended sequence and spacing.
At iRostrum, a maximum bid is the highest amount a bidder authorises the system to use on their behalf. The platform then keeps the bidder in the lead at the lowest necessary amount, subject to reserve and competing bids, up to that maximum.
This is consistent with standard auction terminology. Christie’s and The Saleroom both describe max bids as confidential ceilings that let the system bid in increments on the bidder’s behalf. The important part for trust is to explain that a bidder can win below their maximum if lower bids are enough.
A quick bid is the next valid bid shown by the system based on the current bid level and increment rules. It allows a bidder to submit the next eligible bid without typing a custom amount.
This is especially useful on mobile and in fast-moving closing periods. The definition should make clear that quick bid is not a separate strategy; it is simply the platform’s shortcut to the next accepted increment.
