Key TakeawaysFair Isaac Corp. (FICO) stock fell Thursday after disclosures of insiders selling shares in the company.During the past week, two executives at the firm sold FICO shares worth a combined total of more than $8 million.Investors often consider sales by insiders as a sign of faltering optimism in a company's outlook. Shares of Fair Isaac Corp. (FICO), the financial analytics firm known for its credit scores, receded from an all-time high, tumbling 4.2% to log the weakest daily performance of any s ...