Called the 1987 crash with his Super Model, then wrote the book on buying growth at a reasonable price.
Winning on Wall Street: GARP Screen + Super Model Market Timing
Martin Zweig was a finance PhD who became one of Wall Street's most famous market timers. His Zweig Forecast newsletter and 1986 book Winning on Wall Street laid out a two-part method: a stock screen that buys growth at a reasonable price — earnings growth above the S&P with continuation likely, a P/E reasonable relative to that growth, insider buying, and price strength — and a Super Model that times market exposure from monetary conditions (don't fight the Fed), market momentum (10-day advance/decline ratio, 9-to-1 up/down volume days), and the Ned Davis 4% Model on the Value Line Composite. Days before Black Monday, October 19, 1987, the model flashed sell; Zweig went defensive while the market fell 22% in a day. He later ran the Zweig Total Return Fund and stayed famously bullish through much of the 1990s bull market while the model agreed.
Zweig's two-part method: a growth-at-a-reasonable-price stock screen (EPS growth above the S&P, PEG ≤ 1.5, insider buying, RS leadership) and a Super Model that times market exposure from Fed direction, breadth momentum (10-day A/D, 9-to-1 volume days), and the Ned Davis 4% Model.
Method principle · Legend AI synthesis Buy growth at a reasonable price, and let the market's own breadth tell you how much exposure to carry: don't fight the Fed, don't fight the tape.
With the Super Model deteriorating on monetary and breadth readings, Zweig moved defensive days before October 19, 1987, when the market lost 22% in a single session.
The lessonBreadth and monetary data, not opinion, timed the exit — the model decides exposure, not the forecaster's gut.
With the Super Model bullish and the Fed accommodative, Zweig stayed heavily invested in screened growers through the decade's long advance.
The lessonWhen the model and the tape agree, stay with the trend — the hard part of timing is not leaving too early.
Legend AI implements Martin Zweig's published methodology for educational pattern detection. Not affiliated with or endorsed by Martin Zweig. Not investment advice. Full disclaimer →