The $VIX is at 16.40 and rising. At some point, it becomes a leading indicator (not co-incident) and kicks in the sell algorithms. I'm expecting it somewhere around 16.50, but that's just a seat of the pants estimate.
The drops today were sudden and precipitous...characteristic of specialists pulling bids in an eyewink. The indexes would then labor upward for a few bars, and then get hit with another round of bid pulling. Neither technical trends nor fundamentals account for what is happening. It is a "quant" driven market. Any asset that gets out of line (currency, interest rates, volatility, gold...etc.) could trigger the next algorithm-driven move. This is very dangerous. One algorithm could start feeding on another and drive the whole thing into meltdown, or melt up, too, I suppose. I'm trying to stay ahead of it by keeping my delta slightly biased via adding/subtracting puts and calls as we reach (and cross) the outsides of trading ranges.