When is ur character saved?

In d2 I had a habit of always quitting my game in order to save my character and items when doing trades in order to avoid rollbacks that where very common.

So in poe, is character/items saved when you complete a trade or just when you disconnect form server or on timed intervals or what?

As it is not I always log out when doing high value trades, just in case lol :P

Periodically

OR

Enter a new zone (or just enter town, exact details I do not know)