K is the NYSE Stock Ticker Symbol for BattleCreek, MI based Kellogg Co, the makers of many breakfast cereals (Frosted Flakes, Special K, Froot Loops, Corn Pops, etc), and the college staple of choice (next to macaroni and cheese), Pop-Tarts. They were IPO'd on 5/12/1959 (thank you nyse.com), which makes sure that they are here to stay.