Jana Partners took a stake in the struggling potato company. Shares of Lamb Weston (LW 9.63%), one of the world's largest producers of frozen potatoes, were moving higher today on news that an activist investor had taken a stake in the struggling food stock. As of 11:19 a.m. ET, the stock was up 9.9% on the news. Jana sees an opportunity According to a report in The Wall Street Journal, Jana Partners has accumulated a roughly 5% stake in Lamb Weston with the intention of pushing the company to consider a sa ...