Nothing will happen, as I will be able to fullfil the margin requirement. What do you think will happen?
Update: I now even did a trade just to test this out, and it worked as expected by me!
And here's the screenshot. Compare this to the previous screenshot of today: the total credit increased by about $65 (it was just 1 contract):
Yes but margin went down so not a valid test. Does not indicate using collected credit.
-- i kind of hate alot of talk.