You cannot buy fractions directly. However, with all savings plans we also buy fractions of ETFs for you so that your savings amount can be fully invested. As long as your savings plan is active, these fractions are repeatedly combined to form whole number securities.

If you want to sell an ETF that has been acquired via a savings plan and therefore contains fractions, you can of course also sell the resulting fractions again together with the whole position. Beyond that, no fractions can be sold.