I was watching the action the whole time on Friday had a bunch of stuff up I was watching, but the most interesting was the ES quotes vs the S&P cash index. Pretty obvious they were trying to use the futures to push up the index and were running into some trouble (the price differential they trade at shrank to almost nothing), the trending traders (I guess most are bots) do this and most of the time a fire gets lit under the cash index (so, the stocks themselves). The fire didn't get lit, the cash index refused to be pushed up further, so the trending players had to bail.
It was mostly just these super-short term players not being able to push up the index anymore and having to bail out of the effort, IMO. It means a lack of buyers in the underlying stocks on a longer timeframe, which since the weekend was coming up would mean a couple of days. I'm not sure that means much beyond Friday, though, since that G20 summit might just be making buyers nervous. Might be, though, that we've ran out of buyers for longer than that. I'll just have to wait until Monday to know anymore than that.