Why tick breadth fails as a market personality

Each tick still pairs a buyer with a seller

The exchange tick tallies how many names last printed higher versus lower. That market-breadth count is not a direct read of leftover supply, because each print still pairs a buyer with a seller.

An uptick can occur without shrinking available supply. That includes a buy that meets a resting sell, and a short sale that temporarily adds borrowed shares that later return to the lender.

The tick is an exchange breadth print that nets last-sale upticks against downticks. It does not report remaining supply on the book.

A closing print is a weak one-day forecast

Recasting the tick as a sentiment or demand gauge still leaves the closing print highly variable. The closing-tick, the end-of-session breadth print often treated as late-day buying or selling strength, is a weak one-day forecast.

Absolute session-extreme triggers near +1,000 or between about -800 and -900 can flag rare optimism or pessimism. Those prints also appear mid-trend rather than only at a start or end.

Deviation bands mark rare readings, not a mood

A moving average here is a fixed-lookback smoother, a roughly quarterly 65-session average applied to closing or session-extreme tick values so level and drift can be compared with price.

A 65-session moving average of the closing tick wrapped in plus-or-minus two-standard-deviation Bollinger-style bands isolates about 4.6 percent of readings. Those outliers are framed only as a possible direction change over the next one to three sessions.

Bollinger bands, as used here, are plus-or-minus one- or two-standard-deviation envelopes around that average. They mark statistically rare tick readings rather than a durable trend.

A session can print both extremes

The session-tick-range is the day's highest and lowest tick prints and their difference. It is used to test whether optimism and pessimism can coexist.

Session-high and session-low tick series, plus their difference, swing from one range edge to the other. They fail a visual stationarity check when a sloping linear fit is applied. Stationarity asks whether a plotted series wanders around a flat mean; a sloping linear fit marks a non-stationary tick path.

Extreme session-high and session-low ticks can occur on the same day. A large optimistic print does not rule out a large pessimistic print in the same session, and a single intraday extreme is an unreliable trigger.

Envelopes can split while prices fall

A quarterly-length moving average of the session-high tick can rise, and its own standard-deviation width can shrink, even while the related index futures fall by 50 percent and broader price volatility rises.

In a sharp mid-2002 decline, session-low ticks became more negative while session-high ticks rose. Moving-average envelopes of the two series can show concurrent optimism and pessimism rather than one market mood.

Editorial reading: a personality story is not allowed to stand until that quarterly average and its deviation bands survive these same-session contradictions and this price-breadth split.