What is the Sharpe ratio (90-day estimate)?

Sharpe ratio measures return per unit of risk taken: mean excess return over the risk-free rate, divided by its volatility.

Why risk-adjusted return matters more than raw return

Two tickers can post the same 20% gain over 90 days with wildly different Sharpe ratios — one earning it through a smooth climb, the other through a rollercoaster of drawdowns most holders wouldn't have stomached. Sharpe isolates that difference: it is the honest answer to "was this return worth the ride?", which a raw percentage-return number cannot tell you on its own.

Live example: AAPL's current 90-day annualised Sharpe estimate is 2.47. See the full AAPL forecast for the risk metrics this figure sits alongside.

Sharpe ratio and position sizing

A high raw expected-growth number paired with a weak or negative Sharpe ratio is a signal to size down, not up — the model's own Kelly-based position sizing already discounts for volatility, and a poor Sharpe reading is the same underlying risk showing up from a different angle.

Frequently asked questions

What counts as a good Sharpe ratio?

Above 1 is generally considered solid risk-adjusted performance; below 0 means the position lost money even after accounting for how volatile it was.

Why use a 90-day window instead of 1 year?

A shorter window reacts faster to market-conditions changes but is noisier — read the 90-day estimate alongside the 1-year figure, not in isolation.

Can a stock have a big gain and a bad Sharpe ratio?

Yes — the same return earned through a volatile, drawdown-heavy path scores a lower Sharpe ratio than the same return earned through a steadier climb.

See it on a ticker

AAPL analysis shows this metric in context, or browse all S&P 500 tickers.

Related terms

Educational research only — not investment advice.