In a nutshell, it's because the retailer is projecting slower growth for this quarter than what Wall Street was expecting.
Earnings of $1.68 topped the market's anticipation of $1.63 per share while revenue of $1.87 billion bested the Street's guess of $1.83 billion. But, Ralph Lauren warned that its operating margins will take a hit as it invests more money in growing the company.
At one point, Ralph Lauren's stock was down as much as 6 percent Friday. It rebounded to $149 a share, or down 2 percent for the day.
John Kosar, director of research at Asbury Research, thinks shares can get up to as much as $158 before falling. He sees support around the $134 level.
"I would be much more interested at looking to buy this around $134 a share," Kosar said. "If we can get down to $105 a share, that's an even better place."
"I would be really careful trying to buy this for a $6 or $7 bounce," added Kosar. "I would rather wait and see us drop another $10 a share."
Liz Dunn, senior analyst at Macquarie Capital, covers Ralph Lauren. She views the stock's drop on Friday as a buying opportunity and has a 12-month price target of $180.
"I actually was really encouraged by this call despite the guidance, which was obviously disappointing," said Dunn about the company's earnings call. "But, what I heard that was encouraging was this acceleration in growth."
Dunn likes that Ralph Lauren plans on increasing its advertising and its focus on leather goods. "This investment spending ultimately should drive operating efficiencies beyond this year," she said.
To see the full discussion on Ralph Lauren, with Kosar on the technicals and Dunn on the fundamentals, watch the above video clip of CNBC's "Street Signs" "Talking Numbers" segment.
[Disclosures: Macquarie Capital (USA) Inc. or one of its affiliates received compensation for products and services other than investment advisory services from Ralph Lauren Corporation during the past 12 months. During this time, Macquarie Capital (USA) Inc. or one of its affiliates provided non-securities services to Ralph Lauren Corporation.]