That was followed by a further 150-point gain and another loss of more than 100 points.
It was the biggest point loss ever but far from a record in percentage terms.
The Dow finished with a loss of almost 19 points.
All told, a loss of three points - but not a single jerk!
They almost closed the gap, but ended up with a one point loss.
The Dow finished the week with a net loss of 76.26 points.
The two sell programs combined gave the Dow a loss of 48 points, the research firm said.
They represented a combined loss of more than 14 points on the Dow.
By midday it was down and closed with a loss of 237.72 points, at 37,222.60.
Failing to catch all 7 tricks results in a loss of 21 points.