Here's what I don't get...
IB was concerned about these intraday traders "bringing the firm down".
First of all, I thought those were a minority of smaller traders.
And I thought they were responsible for their margin calls, not IB, but obviously there's something that's happened which slammed IB in the pocketbook (I am speculating).
And IB's automatic liquidation should be fast enough during active intraday periods and, if it isn't, then that also applies to Swing positions where overnight market liquidity is usually very poor so I would think liquidating would be much more of a challenge than during the day sessions.
And the majority of larger traders, who Swing or invest, appear to me to represent a significant risk during highly volatile periods, but we've already covered that.
$3500 for ES ?? Yes, something's got to give and the more aggressive firms will get a portion of IB's business if they don't give some timeframes or indication when this intraday madness will stop.
I can get 3 or 4 times the buying power at another firm, and I will use that to scale in and out very carefully in markets like ES where a "big volatility intraday move" might be 20 ticks.
I can spend an hour waiting for ES to move 3 ticks and, anyway, that's why I don't daytrade it, but that's another topic.

a sense of humor helps. FS