Efficient market hypothesis

The efficient market hypothesis holds that prices reflect available information. It matters legally because the fraud-on-the-market presumption of reliance in securities class actions rests on it.

history and doctrine · updated 2026-09-08

See also

• Fraud on the market — The fraud-on-the-market doctrine presumes that investors in an efficient market rely on the integrity of the price, so a plaintiff…
• Price discovery — Price discovery is the process by which trading aggregates dispersed information into a price. Manipulation is harmful precisely b…

Terms that refer here

Fraud on the market

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