Shares of McKesson jumped to their highest price since 1999 on Wednesday, the day after the drug wholesaler posted better-than-expected quarterly results and raised its outlook for the full year.
The stock was up nearly 11 percent in late-morning New York Stock Exchange trade. Earlier, the shares rose as high as $66.47.
Citi analyst Charles Boorady upgraded his rating on the stock to "buy" from "hold," citing strength in the company's information technology business.
JP Morgan analyst Lisa Gill, who has an "overweight" rating on the stock, said McKesson had shown sustained improvement in profitability in recent quarters.