S&P Emini futures have surrendered all of the day's gains in the last 25 minutes, dropping 40 points to trade 5,605.00. Nasdaq futures have dropped a quick 1.1%, vs 0.8% for S&P eminis.

• As that suggests, Tech is a key laggard, off 0.9% on the day, with Real Estate and Consumer Staples also in the red; energy (+1.2%) is leading on the back of a rally in crude oil, with notable gains seen in Industrials and Financials.
• No headline catalyst is evident - and there is very limited spillover into other asset classes - though 14:38ET saw the biggest apparent equity sell program of the day, totalling 996 NYSE names.
• Support for September Eminis comes in at 5561.25/5508.99 Intraday low / 50-day EMA.