I haven't been trading long enough to have experienced a 9/11 or a 1987 crash. Can someone tell me what the worst ever 1-minute S&P future return was, or the biggest 1-minute spike in terms of the VIX was, in terms of percentage? How fast does one need to be in terms of automated systems to clear out in terms of execution now? In theory, the markets could go illiquid and blow up, but when the dow was dropping 1k points, even the 1-minute bars seemed orderly in 2008. At work, we were all on red alert and even our mediocre execution platform seemed to avoid getting run over in 2008.