DEFINITION of 'Alpha Risk'
The risk in a statistical test that a null hypothesis will be rejected when it is actually true. This is also known as a Type I error. The best way to decrease alpha risk is to increase the size of the sample being tested with the hope that the larger sample will be more representative of the population.
BREAKING DOWN 'Alpha Risk'
An example of alpha risk in finance would be if one wanted to test the hypothesis that the average yearly return on a group of equities was greater than 10%. So the null hypothesis would be if the returns were equal to or less that 10%. In order to test this, one would compile a sample of equity returns over time and set the level of significance. If, after statistically looking at the sample, you determine that the average yearly return is higher than 10%, you would reject the null hypothesis. But in reality, the average return was 6% so you have made a type I error. The probability that you have made this error in your test is the alpha risk. This alpha risk could lead you to invest in a group of equities when the returns do not actually justify the potential risks.

Hypothesis Testing
A process by which an analyst tests a statistical hypothesis. ... 
Type II Error
A statistical term used within the context of hypothesis testing ... 
Null Hypothesis
A type of hypothesis used in statistics that proposes that no ... 
Type I Error
A type of error that occurs when a null hypothesis is rejected ... 
Beta Risk
The probability that a false null hypothesis will be accepted ... 
PValue
The level of marginal significance within a statistical hypothesis ...

Investing
Hypothesis Testing in Finance: Concept & Examples
When you're indecisive about an investment, the best way to keep a cool head might be test various hypotheses using the most relevant statistics. 
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What is a Null Hypothesis?
In statistics, a null hypothesis is assumed true until proven otherwise. 
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How Statistical Significance is Determined
If something is statistically significant, itâ€™s unlikely that it happened by chance. 
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Explaining Standard Error
Standard error is a statistical term that measures the accuracy with which a sample represents a population. 
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Alpha and Beta for Beginners
An indepth look at what alpha and beta are and what they measure. 
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How Does Sampling Work?
Sampling is a term used in statistics that describes methods of selecting a predefined representative number of data from a larger data population. 
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What is Systematic Sampling?
Systematic sampling is similar to random sampling, but it uses a pattern for the selection of the sample. 
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What is a Representative Sample?
In statistics, a representative sample accurately represents the makeup of various subgroups in an entire data pool. 
Trading
Bettering Your Portfolio With Alpha And Beta
Increase your returns by creating the right balance of both these risk measures. 
Investing
What's a TTest?
TTest is a term from statistics that allows for the comparison of two data populations and their means. The test is used to see if the two sets of data are significantly different from one another. ...

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