Last week, a "strong sell" rating from short-seller Spruce Point Capital drove Kratos Defense & Security (NASDAQ: KTOS) stock down 11% as investors reacted to accusations of "tremendous value" destruction, and a prediction that Kratos stock could drop 40% to 70%.This week, Kratos fired back.On Monday, Kratos issued a statement disputing "a report on the Company that has recently been published in the market place" -- presumably referring to Spruce Point's report.