Fair value (30.0x) multiplies each year's earnings per share by a growth-based multiple: steady growers (5–15% a year) get 15x, faster growers get their growth rate as the multiple (capped at 30x), and slower growers step down below 15x. AMZN has grown earnings about 37.1% a year, so the line uses 30.0x.

Typical multiple (40.0x) is what investors have actually paid for AMZN: each of the last 20 fiscal years' average share price divided by that year's earnings per share, taking the median (loss years excluded). It shows how the market has historically priced this specific company, next to the general fair-value rule.

Today's multiple (20.9x) is what the market is paying right now: the current price divided by the last twelve months of earnings (the four most recent reported quarters). Compare it to the two reference multiples above to see whether today's pricing is rich or cheap.

Earnings are adjusted figures on the same basis analysts forecast, built from reported quarters; years beyond the last completed fiscal year use the analyst consensus (dashed). The verdict calls a stock over- or undervalued only when the price sits more than 10% from the fair value line.