Last Thursday, October 11, the market selloff accelerated shortly after 2 pm when as we reported at the time, the market was unexpectedly hit with the biggest sell order since the May 2010 flash crash, when the NYSE uptick minus downtick index, hit a print of -1,793. The result was a 600 point plunge in the Dow in minutes.

Why do we bring this up? Because recall that earlier today, when discussing Marko Kolanovic’s latest bullish forecast on the market, according to which the systematic selling was over and index options hedging was “pointing in an upward direction”, we said that “all eyes now turn to … the last hour of US cash trading, when risk weakness has emerged in recent weeks.”

Well, at exactly 2:02 pm ET – when the market in recent weeks has started to get wobbly during the afternoon session – the NYSE TICK Index Uptick minus Downtick suddenly tumbled to -1,303 when what until now was quiet day in terms of coordinated stock market selling was hit by a spasm of sell orders as Bloomberg’s Andrew Cinko noted.

The massive sell order almost instantly sent the Dow, which had been gradually fading all day, into negative territory.

The reason the low print was noticed is because readings of more than 1,000 in either direction get attention as a sentiment indicator. “Specifically, multiple selling or buying spasms accompany meltdowns and meltups, and that’s certainly true of last week’s tough drops.”

So with Friday’s first major sell order having passed, and the Dow rebounding back into the green, the question is whether this was it for today’s selling, or are even more aggressive sell orders on deck as we enter the last hour of trading.