 Anpac Bio-Medical Science NASDAQ:ANPC and Quest Diagnostics NYSE:DGX are both medical companies, but which is the superior stock? We will contrast the two businesses based on the strength of their earnings, profitability, analyst recommendations, valuation, dividends, risk and institutional ownership. Insider and Institutional Ownership 89.7 of Quest Diagnostics shares are held by institutional investors. 1.5 ... 