Oct 13 close Sign in

Trader and author specialising in momentum indicators

William Blau

William Blau is a trader with expertise in momentum indicators who founded an engineering firm before trading, and holds degrees in electrical engineering from NYU and systems engineering from the University of Pennsylvania. He introduced the True Strength Index in Stocks & Commodities in November 1991 and expanded his work in Momentum, Direction, and Divergence (Wiley, 1995).

What they argue

  • Double-smoothing price changes gives a momentum line stripped of high-frequency noise that still shows trend direction, size of moves and turning points.
  • TSI can be seen as a cross between an RSI and a MACD that keeps desirable properties of each.

Sources

Wiley: Momentum, Direction, and Divergence - author informationTraders.com: True Strength Index, S&C V.9:11 (1991)Traders.com: Trading With The True Strength Index, S&C V.10:5 (1992)

Summaries are Be The Puck's paraphrase of public material. Be The Puck has no affiliation with the people listed.

Books and papers

  • Momentum, Direction, and Divergence (1995)

The full reading list

Blau True Strength Index (25, 13) zero line

Rule and full record

Momentum · daily

Blau's True Strength Index smooths daily price changes twice and divides by the smoothed size of those changes. Hold while it is above zero.

Calls right29%56,707 closed calls on 377 stocks.
Beat buy and hold (Sharpe)86 of 375On raw return: 68 of 375.
In right now148 of 377As of the Oct 13, 2026 close.

Best risk-adjusted results against buy and hold:

APPOUTSUPXOUTLACOUTSTHHINRKLBOUTACOUTETHOUTBTEINGPROINNPCEOUTCURAOUTBTCINAll 377 stocks →

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