Alpha
Alpha measures the performance of a portfolio compared to its reference indicator. Negative alpha means the fund performed less well than its reference indicator (e.g. if the indicator increased by 10% in one year and the fund increased by only 6%, its alpha is -4). Positive alpha means the fund performed better than its reference indicator (e.g. if the indicator increased by 6% in one year and the fund increased by 10%, its alpha is 4).