If you plan running your banners on Adwords platform, you must follow their guidelines and one of them is:
"Animations can loop or repeat, but must stop after 30 seconds."
Of course that all our banners are compatible with Adwords so to comply with that rule you simply need to check the "Stop slide" option for the last slide from the banner.
If you're using the Banner Generator, all animated banner sets made from our templates already have that option checked so you don't have to worry about that.
However, if you're creating an animated banner set from scratch, you'll need to manually "Edit as new" each banner from the set to access the "Stop slide" option and enable it.