First of all, thanks for the discussion.
Quote from alanm:
Looking at one of the most liquid contracts in the world - the ES - current overnight maintenance margin is $3150, or 63 points. Intraday reduced margin at 50% is 31.5 points - just a 2.5% move. 25% would be just a 1.25% move. $500 (like some firms advertise) is just 0.8%.
Picture a 9/11-type event, only this time directed at the CME, or perhaps just taking out bundles of communications circuits sufficient to prevent trading. Is there any doubt that, upon resumption, the market will gap -2.5%, let alone the lesser amounts mentioned above? Thinking specifically about IB customers, it doesn't matter that the NYSE/AMEX/NASDAQ or other futures venues might remain open if the big positions need to get to a phone to hedge (especially if their phones are affected by the disruption) - those markets could easily sell off by these figures by the time they get hedged. Were someone to take out NY at the same time, the scenario is even worse.
If it happens within the trading session, yes it is possible. Otherwise no as it becomes an overnight issue. However I think the positive (buying) big sharks are more worried than you and me since it is them who has huge positions.
Anyway, this is just an extraordinary case (I will discuss more in latter paragraphs).
For the $500 margin case (16% of the normal overnight MM), you don't have to go anywhere near that extreme. The ES can (and does) move hard by 10 points occasionally on news, during which everyone piles on with sell orders, and one could easily imagine capacity issues at IB and/or CME causing delays long enough to cause trouble.
Let's take a real suggestion (first attempt) in a real case. How about suggesting:
- $1300 (33%) min required margin with $1000 min maintenance margin?
[To me, I would accept even $1100 required margin (
if a client with good past records requests), but the maintenance margin still remains at $1000.
If you think it is unacceptable, forget it!]
- For people who are less aggressive, they may manually set more required margin (or maintenance margin) up to 3938 required and 3150 maintenace
- a warning is issued if it (nearly) reaches the mainenance level
- a focred auto-liquadation is executed immediately ONCE it falls below the caution level (set by IB).
- for people who have bad records in the past (ie being forced to auto-liquidation before they can resolve the problems), the margin level will be raised accordingly until their situation (eg their risk management) is improved for a certain period
If another 9-11 incident happened within the trading session, the losses would be minimal. We won't expect this thing would happen, say, for next 5-10 years.
So should just 1 exceptional loss for every 5-10 years frighten you not to lower the margin level by just a bit (I'm not asking for $500 margin

), not to say you may get more clients and more trades to more than cover this exceptional loss many times.
As a trader, we won't be frightened away just by exceptional cases and not to trade at all. Why a firm will?
Extend these cases to far less predictable, stable, liquid markets and contracts, and you have a potential for serious trouble.
Raise the margin level.
Flexibility is the key!
