Given that 1 would represent perfect correlation, that implies most hedge-fund styles are rising and falling in near-unison.

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"There's been a near-perfect correlation in equities gains each time the Fed induced more liquidity into the marketplace, " said Mark Luschini, chief investment strategist at Janney Montgomery Scott.

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That said, it's by no means a perfect correlation.

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If two stockmarket indices always move linearly in the same direction at the same time, and the relative size of their movements is always the same, they have a perfect correlation of 1.

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That said, there was a clear (but certainly not perfect) correlation between intellectual horsepower and V100 ranking.

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The correlation is as perfect as it gets in the markets.

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The correlation was very strong, but not perfect.

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Even the Yale-like portfolio had a correlation of more than 0.9 (where 1 is a perfect fit).

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