In the Event Management Guide available via Help, explains it as follows:
Specify How Participants View Market Information
You enable a starting gate to hide all market information from participants until they have successfully
submitted one bid. The bid must satisfy the starting gate criteria. The information is hidden on the bidding
console, Event Details page, and the Lot Details page. This information includes the bid graph, the lead bid,
and the Bid History table.
• Do not enable a starting gate: All participants can always see market information during open bidding.
• Enable a starting gate for each lot: There is a starting gate for each lot, which means participants cannot see
the hidden information mentioned above until they enter a qualifying starting bid on the lot.
• Enable a starting gate for the entire auction: There is one starting gate for the whole auction including all lots.
Participants cannot see the hidden information mentioned above until they enter a qualifying starting bid,
and they can see this information equally for all lots without having to enter a qualifying starting bid for
each.
You use this feature in combination with the ceiling price in order to restrict the display of market
information to competitive participants.You set the ceiling price during lot and line item creation. For more
information, see “Creating Content Items” on page 68. The ceiling price is the highest