If I buy a put the margin required is the entire premium (harsh but fair)
If I sell a lower strike Put (same expiry of course) so making a Put Spread, then my max loss is the net premium, does IG then return any margin to me?
net premium would be best, or maybe there a formula used.
if I try to trade out if one option only, and so unpair the options I guess they cld ask me for more premium to do so? (Think i May have just answered my own question)