The selling pressure was on all day as the stocks sold off from the open right into the close.
Some of the stronger names such as AAPL and NFLX held support levels for the morning, but afternoon sellers started hitting around 14:30, taking AAPL below the support from the previous day. The loss of these levels resulted in stop losses getting hit and an acceleration to levels below $390.
A similar scenario in NFLX when the 13:00 lows were taken out and selling to the $257 level and GOOG to the $590 support levels.
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