A proportion decline as the measured target gives a little more reasonable outcome; the S&P lands at around 500, but the Nasdaq comes in at 900 (and the Nasdaq 100 at 675). Whether these levels are reached will depend on the current mood, but given the market was prepared to give the jobs data a chance before Apple spoiled the party suggests an end (but not 'the end') is close to hand.
Breadth indicators point towards further declines, technicals of the Bullish Percents and Summation Indices have plenty of downside room
Prepare for a counter-rally, but it's unlikely to last anything longer than a few days.
Dr. Declan Fallon, Senior Market Technician, Zignals.com the free stock alerts, market alerts and stock charts website