Alpha measures how much an investment beat (or trailed) what you would have expected from its risk alone. It is the "skill" portion of a return — the part not explained by simply riding the market up and down. Positive alpha means you did better than the risk you took would predict; negative alpha means worse.
Alpha is always measured against a benchmark (often a broad index like the S&P 500) and after accounting for how much market risk you carried — your beta. Example (illustrative): the market returns 10%, and a stock with a beta of 1.2 would "deserve" about 12% for the extra risk it carries. If it actually returned 15%, the roughly 3 percentage points above that expectation is its alpha. If it returned 9%, its alpha is negative — it underperformed the risk it took.
Real, repeatable alpha is rare: most apparent outperformance turns out to be extra risk in disguise, or luck that doesn't repeat. Measured over too few trades, a high alpha is statistically meaningless. This is exactly why a track record has to be judged over a large sample and compared to a fair benchmark — a lesson that applies to any tool claiming an edge, including ours.
Alpha is the honest question to ask of any forecasting product: does it beat a simple benchmark after adjusting for risk, over enough samples to matter? That is why we publish a backtest track record and pair returns with risk measures like the Sharpe ratio rather than headline returns alone. None of this is investment advice.
Beta measures how much an investment moves with the market — its market risk. Alpha measures the return earned above (or below) what that risk would predict. Beta is exposure; alpha is the leftover skill or luck.
Positive alpha is desirable, but over a small number of trades it can be pure luck. Alpha only becomes meaningful over a large sample and against a fair benchmark, after adjusting for risk.
Markets are competitive, so genuine, repeatable outperformance is rare. Much apparent alpha is really extra risk in disguise or luck that doesn't persist — which is why a long, honest track record matters more than a single good result.
Browse all S&P 500 tickers to see this metric applied to individual companies.
Educational research only — not investment advice.