What it is
Every scored stock has its Quality Score written down once per trading day. The ticker page charts that record in a pane under the price, as far back as five years, and a strip of bars shows the check count for the last sixty sessions. You can see whether a score of 15 is a level the stock has held for a month or a spike from this morning.
How persistence is scored
Persistence reads that same record. It takes the median, or middle value, of the last twenty recorded days. A median of 12 or more earns two points, and 9 or more earns one point. The values it reads are bases. A base is that day's score with its persistence points taken back out. That way this part of the score cannot build on itself week after week.
It needs ten days of record before it pays anything, and it never subtracts. A stock that broke out this morning simply has no history to earn on. Being new costs it nothing. It just has not earned this part yet.
How to read it
A flat, high line is a stock that institutions have held up for weeks. A line that steps up in the last few sessions is a stock that just changed, which is what the Fresh list is for. A ragged line swinging between 6 and 14 is a choppy stock whose checks keep flickering. Persistence will pay it little whatever today's number says. The history records what the score was. It does not forecast what it will be.