[fny]

If I have multiple billions at stake, I would assume my broker would be even more demanding of responding within a time frame. Note, I'm not calling for automatic liquidation, but rather some timeframe wherein discussions must be held or else the posted collateral is seized.

[rtkwe]

The problem there is at that level you're also a significant source of money for both the company and whoever gets bonus/commission on the money you bring in so suddenly there's a lot of reason to not make you annoyed enough to take your business elsewhere.