The big contract spiked as well, just not the extra hundred points. This whole situation is a mess. I give CME credit for making a quick decision, but a lot of people will be treated unfairly as a result.

Quote from Lobster:
That's true if ESH3 was his only position, but if he had other contracts or stocks in his account, they might have been liquidated because of the huge (albeit temporary) drop in account equity. Let's say I have an IB universal account with 20 different long stock positions and short ESH3 as a hedge. The spike would have caused the ESH3 to be liquidated at a loss of say $4000 per contract, way more than maintenance margin. Now my equity is suddenly negative or way too low to meet the stock margin requirement. The broker will sell all my stocks (after hours!) and leave me with an additional huge loss there.

Quote from larrybf:
Personally i was not in the market during this particular spike fiasco. however , i have been on the wrong side of CME NONSense BEFORE and in my opinionif enough of us mid size retail futures traders took our business away from the emini and started trading the CBOT dow futures this crap might stop. BUT it will require a bunch of us to mutiny. Unless we reduce emini volume by 100,000 contracts a day probably nothing will happen. ANYWAY, as soon as the spread on the dow futures gets as small as emini ES i am gonna switch.