DEFINITION of 'Price Efficiency'
The premise that asset prices are efficient, to the extent that they already factor in or discount all available information. The theory of price efficiency follows from the efficient market hypothesis, which holds that since markets are efficient, it is nearly impossible for investors to "beat the market" on a consistent basis.
BREAKING DOWN 'Price Efficiency'
The three versions of the efficient market hypothesis (EMH) are all based on varying assumptions of price efficiency. The weak form of EMH claims that the prices of publiclytraded assets already reflect all available information, and past prices are of little value in predicting future trends. The semistrong version of EMH holds that while prices are efficient, they react instantaneously to new information, while the strong version of EMH maintains that asset prices reflect not just public knowledge, but private insider information as well.

Market Efficiency
The degree to which stock prices reflect all available, relevant ... 
SemiStrong Form Efficiency
A class of EMH (Efficient Market Hypothesis) that implies all ... 
Weak Form Efficiency
One of the different degrees of efficient market hypothesis (EMH) ... 
Efficient Market Hypothesis  EMH
An investment theory that states it is impossible to "beat the ... 
Discounting Mechanism
The premise that the stock market essentially discounts, or takes ... 
Strong Form Efficiency
The strongest version of market efficiency. It states all information ...

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Market Efficiency Basics
Market efficiency theory states that a stockâ€™s price will fully reflect all available and relevant information at any given time. 
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Efficient Market Hypothesis
An investment theory that states it is impossible to "beat the market". 
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Explaining Economic Efficiency
Economic efficiency is achieved when every resource is optimally allocated to minimize waste and best serve each person in that economy. 
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Explaining Efficiency
Efficiency refers to the ability to make something with the fewest resources possible. 
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Investopedia Explains Fractal Markets Theory
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Efficiency Ratio
There are many types of efficiency ratios, but all measure how well a company utilizes its resources to make a profit. Business managers use these ratios to determine how well they are operating ...

What does the efficient market hypothesis assume about fair value?
Found out what the efficient market hypothesis says about the fair value of securities, and learn why technical and fundamental ... Read Answer >> 
What are the primary assumptions of Efficient Market Hypothesis?
Find out about the key assumptions behind the efficient market hypothesis (EMH), its implications for investing and whether ... Read Answer >> 
Why does the efficient market hypothesis state that technical analysis is bunk?
Learn about why there are strong conceptual differences between the efficient market hypothesis and technical analysis about ... Read Answer >> 
What does the Efficient Market Hypothesis have to say about fundamental analysis?
Find out what the efficient markets hypothesis has to say about fundamental analysis and how recent finance research has ... Read Answer >> 
What are the differences between weak, strong and semistrong versions of the Efficient ...
Discover how the efficient market theory is broken down into three versions, the hallmarks of each and the anomalies that ... Read Answer >> 
Has the Efficient Market Hypothesis been proven correct or incorrect?
Explore the efficient market hypothesis and understand the extent to which this theory and its conclusions are correct or ... Read Answer >>