Alpha

• A measure of the volatility, or systematic risk, of a security or a portfolio in comparison to the market as a whole.
• A beta of 1 indicates that the security’s price will move with the market. A beta of less than 1 means that the security will be less volatile than the market. A beta of greater than 1 indicates that the security’s price will be more volatile than the market.
• For example, if a stock’s beta is 1.2, it’s theoretically 20% more volatile than the market.” Managing Portfolios in Uncertain Times 

“ALPHA:

• A measure of performance on a risk-adjusted basis. Alpha takes the volatility (price risk) of a mutual fund (stock) and compares its risk-adjusted performance to a benchmark index.
• The excess return of the fund relative to the return of the benchmark index is a fund’s alpha.

·A positive alpha of 1.0 means the fund has outperformed its benchmark index by 1%. Correspondingly, a similar negative alpha would indicate an underperformance of 1%. Likely does not exist after taking fees into account.” Beta, Will Kenton