The Greek debt crisis finally spilled over in full force to U.S. markets, aided and abetted by extreme statements emanating from such esteemed and prominent voices as Muhammed El-Erian of the large bond investor Pimco, who warned that Greece could be just the beginning of sovereign debt catastrophes. In the space of minutes, the major U.S. indices plunged more than 10%, fueled by the same programmatic electronic trades that were part of the battering in late 2008 into 2009. And then in the space of 15 minutes, they recovered, without — it’s fair to say — much human decision-making during that interval (and if an individual even tried trading during those 30 minutes, they would have found it difficult or impossible, as web sites such as schwab.com were completely overwhelmed with traffic).