| Multiple Unit Auction | go to Help:Contents  |
| An auction where more than one units are being sold is called multiple unit auction. In other words, auctions in which available quantity is more than 1 are multiple unit auctions. Rules for a multiple unit auction are slightly different than the regular single unit auction. |
 Reserve price can not be set for a multiple unit auction. |
| Multiple unit auction can have multiple winners. |
| In multiple unit auction, a bidder specifies the maximum bid per unit (as in single unit auction) and number of units (quantity) desired. This quantity can be 1 or more up to the available quantity of the item in listing. |
A bidder can not lower his/her "total bid price" (maximum bid multiplied by the number of units for which he/she is bidding) in subsequent bids.
For example, you bid $1 for 3 units (total bid price $1 x 3 = $3) on a multiple unit auction. The total bid price of the subsequent bid has to be $3.01 or higher, e.g., it can be $3.01 for 1 unit or $1.51 for 2 units or $1.01 for 3 units. If you place another bid of $1.50 for 3 units (total bid price $1.50 x 3 = $4.50), the subsequent bid has to be of total bid price higher than $4.50 and so on. |
| Winning bidders are selected in order of maximum bid per unit. For example, a bidder who bids $20 for 1 unit is selected over a bidder who bids $10 for 3 units. |
| If two bids are of equal maximum bid amount, the earlier bid is given priority. |
| In a multiple unit auction, if you bid for more than one unit, your bid might result in winning partial number of units. Partial winners have the right to reject the transaction and they are not obligated to complete it. To win all the units you bid on, you need to increase your maximum bid per unit. |
In multiple unit auction, the final price for all bidders is the lowest winning bid.
| For example, consider multiple unit auction with starting price of $10.00 and 5 available units.
|  Mary bids maximum $15.00 on this auction for 3 units. Mary is winning all the desired units and the price at this time would still be $10.00. The minimum bid would be $10.00. |
| Jack bids maximum $15.00 on this auction for 3 units. At this time, Mary will still be winning all the desired units. However, Jack will win partial units, 2 out of 3. Although, Mary's and Jack's bids are of equal maximum value, the earlier bid is given priority. The price at this time for both winners would become $15.00, the lowest winning bid. The minimum bid will become $15.50 (current bid/price + incremental bid). |
| Susan now bids $20.00 for 1 unit. At this time, Susan is winning 1 unit, Mary 3 units and Jack 1 unit. The price at this time would still be $15.00 for all 3 winners, the lowest winning bid of Jack. The minimum bid will remain as $15.50. |
| Tom now bids $16.00 for 1 unit. At this time, Jack will be outbid. Susan is winning 1 unit, Tom 1 unit and Mary 3 units. The price at this time still remains as $15.00 for all 3 winners, the price which Mary is winning 3 units. The minimum bid will remain as $15.50. |
| Now Jack returns and bids maximum $16.00 on this auction for 3 units. At this time, Mary will be outbid and Jack will win all the desired units. The price for all winners (Susan 1 unit, Tom 1 unit, Jack 3 units) will now be $15.50, the lowest winning bid. The minimum bid will be $16.00. |
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| For a Multiple Unit Auction, even if your bid is outbid, it can become a winning or a partial winning bid if one or more bids higher than your bid are retracted AND / OR if higher bidder(s) change quantities (they bid on) in their subsequent bids. It is recommended that you not bid on multiple active listings at the same time. |
| See also |
| How to buy & sell in an Auction? |
| Incremental Bid |
| Automatic or Proxy Bidding |