(Bloomberg) -- Anchoring stock market predictions on valuation data that go back a century or more is a prescription for failure, according to Laszlo Birinyi.

Things have changed in a world dominated by institutional investors, hedge funds and service industries, and sentiment is as likely to drive prices as anything else, the 72-year-old former Salomon Brothers analyst wrote in a note to clients. Birinyi’s star has risen since 2009 as his bullish forecasts for the Standard & Poor’s 500 Index came true again and again.

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