The premium brand's profits are going up.Shares of cooler and insulated drinkware maker Yeti Holdings (YETI 11.15%) jumped higher on Thursday after the company reported stronger-than-expected financial results for the first quarter. As of 11:15 a.m. ET, Yeti stock was up 12% today.Encouraging margin expansionFor the first quarter, Yeti generated net sales of $341 million, up 13% year over year. The company showed growth across product categories, sales channels, and geographic regions -- everything came in ...