Eli Lilly

Sales grew about 45 percent over the past year, a pace almost no company this size can match. The weight-loss and diabetes franchise is doing the heavy lifting, pulling in tens of billions of dollars a year and still climbing. Demand keeps outrunning what the company can make.

Lilly keeps about 35 cents of profit on every dollar of sales, an exceptional margin for any business. That cash is going straight into new factories and dozens of deals to build the next wave of medicines. Strength like this lets it invest heavily while rivals cut back.

Two drugs, Mounjaro and Zepbound, drive roughly 65 percent of revenue. If demand for weight-loss shots cools or a competitor leaps ahead, the whole story slows fast. One study found nearly half of patients quit these drugs within a year, so staying power is a real question.

The stock trades near record highs, at a big premium to the typical drugmaker even after 45 percent sales growth. At that price there is little room for error, so any stumble in sales or a setback for a newer pill could trigger a sharp drop. You are paying up for the quality.