With bulk-edit, you can modify many transactions at once! In order to access it, click on the three-dotted options button next to search box and select Bulk edit.
You'll be presented with a modified interface with round check-boxes on the left and the following bar at the top:
Clicking on "Bulk actions >" will show all available bulk-options. The ones you'll probably use most frequently are also listed in form of graphical buttons:
Clicking on the round checkmark button on the far left will select all transactions.
Clicking on the square edit button next to the select-all button will open selected transactions for edit.
Clicking on the red trash icon on the right will delete selected transactions (MoneyWiz will ask you to confirm).
Clicking on the x button on the far right will exit bulk edit.
As you click on transactions, you'll notice that they get included in the selection. If you hold Shift key on your keyboard while clicking on a transaction, it'll select this transaction and all transactions in between of the previously selected one.
Please note that bulk-edit has the following limitations. Remember that they only apply to editing transactions but don't apply to non-edit actions such as deletion or setting as cleared:
you can only bulk-edit transactions of the same type: only expenses or only incomes,
it is not possible to bulk-edit transfer transactions or unique transaction types: adjust balance and refunds.