PSA: I've discovered that you should sell your entire hold all at once. I sold 1 unit to see how the event is handling the bonus and it only gave me a bonus for only that 1 unit. I sold off the rest of my hold right after and since it considered the "mission" to be complete after i sold that 1 unit i did not get a bonus for the rest.
So just be warned. I'm sure the rest of you are grizzled veterans at these sorts of things at this point and already knew that this could happen. I'm just new'ish and had to experiment