Constructing the thousand-line advance-decline indicator

Build market breadth as a chart first

The thousand-line indicator starts as daily NYSE advancing and declining issue counts, not as a price overlay. Each session is classified as a three-state breadth day and then added to a running total of +1, 0, and -1 scores. The result is a single line that can be drawn and annotated like any other chart.

How a three-state breadth day is scored

A session scores +1 only when advances are at least 1,000 and declines are below 1,000. A session scores -1 only when declines are at least 1,000 and advances are below 1,000. A session scores 0 when both advances and declines are at or above 1,000, or when both are below 1,000.

Days that clear 1,000 advances or 1,000 declines are treated as the sessions that reveal short-term trader liquidity. That is why only those one-sided bursts receive a nonzero score.

Read the line the way price is read

After the running total exists, breakouts from sideways congestion and formations such as double bottoms, triple bottoms, and trendline breaks on the constructed line are read as shifts in short-term supply and demand. Double top and bottom on breadth is the same reversal language, applied to the cumulative 1,000-line rather than to the cash index.

A thirty-day quad is four bottoms, or the inverse four-top form, inside a 30-day calendar span. That shape is described as uncommon.

What one illustration showed

In the April 30, 1993 to May 24, 1994 illustration, a triple-top breakout on the line in early July 1993 appeared several weeks before the matching S&P 500 trend turn. The same illustration marks a double-bottom breakdown on the line that was not followed by lower S&P 500 prices.

MACD after the line is finished

MACD may be calculated on the finished 1,000-line series after the line itself has been constructed and chart-read. MACD on the breadth line is that overlay on the completed series. It is not the same calculation run on the S&P 500.

Editorial reading

Editorial interpretation follows. The archive workflow finishes the three-state line, applies ordinary chart reading to that line, and only then allows MACD on the breadth line. TradersWeek reads the 1993-1994 panel as an illustration of mixed correspondence with the cash index, including one unmatched breakdown, not as a test of later reliability.