1.UK: One of the four classifications (with beta, gamma, and delta) of the largest and most traded stocks on London Stock Exchange (LSE) under the 'normal market size' classification system.
2.US: Measure of price volatility of a stock (shares). Alpha methodology tries to separate the price movements of a particular stock from those of the stockmarket, and focuses on fundamentals such as the growth rate of stock's earnings per share (EPS). A high alpha score means the stock is expected to remain stable no matter how the stockmarket behaves. See also beta.