GlossaryBy Sverre MoeUpdated 2026-07-21
What is a 90% Up Day?
What is a 90% Up Day?
A 90% up day is a session where two conditions both hold across the eligible universe: up-volume is at least 90% of total up-plus-down volume, and advancing issues are at least 90% of advancing-plus-declining issues. Paul Desmond at Lowry Research defined the criterion; it is meant to flag genuine, broad institutional buying rather than a handful of large-cap names dragging the averages up on their own.
A single 90% up day, on its own, is close to noise; it happens occasionally in almost any market condition. The signal Lowry actually built the criterion around is a pair: two 90% up days within a few weeks of each other, which historically has been one of the more reliable markers that a new bull leg has genuinely begun, distinct from a single sharp bounce inside an ongoing downtrend.
How tickerstance counts them
The count runs over the trailing 20 trading sessions, so the tile always answers how many 90%-up days the market has printed recently, not just whether today itself qualified. It is tracked alongside its mirror signal, the 90% down day (the same two thresholds, inverted, marking broad capitulation), on /data.
As of the July 20, 2026 close, the trailing-20-session count read 0 (None band): no 90%-up session had printed recently, consistent with that day's Weak-to-Caution breadth reading and the absence of any thrust signal on either the McClellan or Zweig Breadth Thrust measures that same session.
Related
- Zweig Breadth Thrust
A rarer, more extreme breadth-thrust companion signal.
- McClellan Oscillator
A smoother, continuously-updating breadth-momentum read.
- Breadth
The subscore both 90%-day measures feed into.