Quote from sail:
IBj your response is well thought out.
There is however something that troubles me about auto-liquidation. If the programming to do so is well thought out everything seems reasonable.
Suppose however, an erroneous quote or closing price causes a low-risk well capitalized account to be auto-liquidated. Who bears the responsibility? We all acknowledge the possibility of auto-liquidation when accounts are first opened. Brokerage account agreements tend to be somewhat one-sided.
In theory it is possible for a large equity credit balance account to be auto-liquidated if it has even 1 share or contract short. (Should that contract be erroneously valued at some arbitrarily large number).
This is where human common sense would look at the account and know that there must be a bad quote.
IB's programming is generally excellent.
They could not have gotten to where they are today by being anything less than the best of the best.
Yes, any human common sense metric can be programmed into an auto-liquidation program. But has it been? If not, who would be responsible for damages caused by an unreasonable liquidation.
IB will take back improper liquidations. If a bad price or other transient gets through our filters, we will pay the bill. If there is a tick that is slightly off and that small difference results in a liquidation, then we don't. It is basically a "reasonableness" test. IB cannot be expected to realize that a 100 stock that prints at 99 is bad data. If it prints at 80, we should (and usually do) trap it.