What happens at 3:50 est?

Outstanding MOC order imbalances get released at that time which causes the short spike in volatility depending how much of an imbalance there is.

 

Incredible to see the grumpy old-timers who think they know more than they do and try to act all cheeky and condescending.

The OP answered a fair question and received a fair answer from a few.

 

%%
And sometime may not know /for days really; SEC or the derivatives cop sued one\ for banging the close...........................

 

3:55 pm to be exact.

 

Nope, 3:50 is the clock-tick on the moves. 3:55 is a residual effect. I have seen it too often for it to be otherwise.

 

3:50 is the Murder Bot. 3:55 is the 2nd Murder Bot. Sometimes he comes out to play, sometimes not.

 

Market on Close orders, MOC, must be submitted to the NYSE by 345 EST. I sometimes see a mild flurry then. But it is the MOC orders on the NASDAQ, which must be submitted by 350 EST, which just about every time create the far larger surge. If one can anticipate which direction that surge is more likely to take, profit! Otherwise might be best to step aside for a minute or two if day trading. Sometimes there is follow through, other times reversal of the initial 350 surge ...