Webconnex Payments maintains a Rolling Balance. This means there must always be enough funds in your balance account to cover any pending debits such as refunds or chargebacks.
Your upcoming payout generally will include any transactions that are completed before 11:59pm pst on Monday night. The deposit will take place on Wednesday and will hit your bank account sometime on Thursday.
If a debit such as a refund or chargeback takes place between Monday night and the deposit on Wednesday, the system will withhold that negative amount from the deposit to ensure there are enough positive funds to cover the negative balance.
Although, if you for example issued a $100 refund on Tuesday, but you had $500 worth of new sales come in, the account isn't in a negative or pending negative state, because that new $500 would cover the $100 pending refund. So no funds would be withheld from the deposit.
Let's look at an example
The below Payout Report (which can be found in your Webconnex Payments account by following these steps) shows the Net Amount of the transactions included in the payout as well as the payout amount. If you look, the sum of the transactions totals $920 more than the actual Payout Amount (seen at the bottom of the screenshot).
It we look a little further at this report, you'll notice the payout occurred on 8/21. There was a $75 sale that happened on 8/20 as well as a $995 refund on 8/20. That $75 sales offset $75 of the refund leaving $920 to be held back in the Rolling Balance account and not deposited in that payout.
You'll also notice in the next payout, that $920 that was withheld on the previous payout is now included in this payout. This is because the Rolling Balance no longer has a negative value.