Horrible. This is the main reason I will not open an account at IB. At Think or Swim/TD if a bad mark on your butterfly put your account in debit, it would not be auto liquidated, but reviewed by a person. If a liquidation is necessary, they would enter the trade as a spread and your loss would be minimal. Did IB liquidate each leg separately?
unfortunately, I don't think TD would liquid as a spread. We look at them as spreads, but the system just see positions in a PM account. In a reg-T account, their are algos that pair off positions to optimize reg-T margin. PM does not work that way.
Yes they basically liquidated the short put of the fly in small lots, causing huge realized losses in the account. Everytime I had to balance the fly manually. I finally closed the fly for a nice 13K profit on the 36 surviving contracts (I downgraded the account to Reg-T that same day). But the loss from the other contracts was about 10K. What a waste of time.