There are opinions on both sides. Some are quite insistent that the SEC etc are not doing enough: eg. Themis, Nanex, most of the ZeroHedge crowd. I think the

There are opinions on both sides. Some are quite insistent that the SEC etc are not doing enough: eg. Themis, Nanex, most of the ZeroHedge crowd. I think the "SEC is doing fine" crowd is less noisy, but probably the majority. Of course, opinions can be influenced by whether the management of the markets is to your financial benefit, and perhaps that's why there seem to be a more people saying nothing: they're heads down, quietly making a fortune ... It's worth noting (again) that the LULD circuit breakers were introduced after the 2010 flash crash, as an attempt by the regulators to "stabilize and support" markets. In some previous events, I think they've worked better than they did on Monday.