Why does my bidding position keep changing?

Bids can be placed on available properties from 00.01 am on Friday (just after midnight on Thursday night) until 11.59 pm on Monday (just before midnight Monday) every week.

You will be able to enter up to 3 bids per week, subject to available properties and can withdraw them during the bidding cycle.

It does not matter if you place your bid as soon as the cycle starts or just before it ends. Your bidding position is determined by your priority for each advertised property and your position can change at any time during the bidding cycle depending on which other applicants choose to bid and whether their banding priority for that property is higher or lower than yours. 

Also, your advertised bidding position is only an indication, as some applicants are auto-bid which means that the system automatically places bids for them if they don't do so themselves.

Any auto-bids are automatically put on just at the end of the bidding cycle, so this is why you may see that your bidding position has changed when the cycle closes.