Shares of leading cereal maker W.K. Kellogg (KLG -2.18%) were up 10% this week as of market close Thursday, according to data provided by S&P Global Market Intelligence.On Monday, the Frosted Flakes maker was added to the Russell 2000 Value, 2500 Value, and 3000 Value indexes, as well as the Russell Small Cap Completeness Value Index.Kellogg's addition means that these indexes acquired a significant portion of the company's shares this week, contributing to the price run-up.More importantly, however, Kellog ...