Apparently if you cancel orders in after hours, depending on who alpaca routed your order to on the backend, the cancelation wont go through until the next day. This means if you try and cancel an order so you can then sell your shares in the after hours, you cannot. Unfortunately I found this out today when trying to sell my shares during an earnings call. I haven’t seen alpaca inform any of its customers of this. Also when I asked if I can prevent my orders from going to these execution routes, I was told they would allow this for a commission fee of .4% despite again no mention of this anywhere.
They really are not leaving out a single opportunity for fucking with people.