Soothing Words about ETF - But Liquidity disappears when we need it most

The market does provide super liquidity that one could never imagine in the past. But when the music stops there will NOT be enough chairs! This type of complacency makes a major debacle even more likely. How many (highly paid) risk managers are really prepared for nearly instantaneous price changes of 20-25 % in all major markets? Tiny slivers of margin will just not be enough to cushion the blow, esp when some potholes open up and a player (or players) fail.
Junk Bond ETFs Are the Future. That's a Good Thing. - Bloomberg