Eg: 100 stocks in an index, 50 on new PF buy signals, bullish percent = 50%.
Changes in the index up and down can only come from the FIRST buy signal given off the bottom. That's what is recorded and all subseqent buy signals are not counted.
Eg: 100 stocks in an index, index at 50%
Over the next week 12 stocks give new PF buy signals, 10 give new PF sell signals
= a net 2% more stocks on buy signal
As each box represents 2%, a net 2% change allows the chart to rise one box.
You use the same 3 box reversal methodology as for normal PF charts, so here it takes a (3x2%) 6% net buy/sell signal to reverse a column upwards/downwards. As a general rule, areas above 70% and below 30% are the two extremes. Above 70% is overbought and below 30% is oversold.
This is worth keeping half an eye on. Note the recent recovery in the NYSE Index....