Constructing a percent-reversal wave filter

A filter before a count

Wave work here starts as a construction problem. The worksheet first locks one percent-filter. That filter is the only rule that may emit an up swing or a down swing. Counting and ratio work wait until those segments exist.

Editorial reading: the aim is not a prettier chart. A named reversal rule, dated extremes, and a closed set of length and percent-change fields make Elliott-style labeling checkable against the same swings every time.

What the worksheet holds

The sheet is built from a contract identifier, trading-session dates, and the open, high, low, and close fields. A separately named cell holds the reversal percentage.

The worked construction sets that named filter to 0.01, a one-percent reversal threshold. The percent-filter is that named reversal fraction applied to the current wave extreme. A contrary move of that size flips the wave from up to down or down to up.

How wave-designation flips

Each bar is labeled up or down. That wave-designation persists until price crosses a switch-level derived from the current apex and the filter.

The apex is the farthest price reached so far in the active wave: the running high while the designation is up, and the running low while it is down. When the designation flips, the apex resets to the new extreme.

On an up designation the switch-level is the apex multiplied by one minus the filter. On a down designation it is the apex multiplied by one plus the filter. Price must breach that switch-level to change designation.

What a completed swing records

A designation change records the wave start date, extreme date, end date, inception price, and terminal apex so each completed swing is bounded.

The inception-point is the prior-wave apex inherited at the moment designation changes. It is the starting price of the new wave.

Closed up and down fields

Closed up waves are numbered and summarized with start and end dates, trading-day length from inception to apex, trading-day length until the opposing down wave qualifies, and percent change from inception to apex.

Closed down waves receive a matching set of fields: sequence number, dates, trading days to the apex, trading days until a same-size opposing correction registers, and percent change from inception to apex.

Wave-length is that count of trading sessions from a wave start to its apex, or from that start until an opposing filtered wave is confirmed.