Exagen (XGN) Stock Analysis & Winston Score

Exagen Inc. is a diagnostics company that makes blood tests to help doctors diagnose and manage autoimmune diseases, especially lupus and rheumatoid arthritis. Its main product is AVISE CTD, a test that analyzes a patient's blood to give doctors a clearer picture of what autoimmune condition they might have. The company sells primarily to rheumatologists — specialists who treat joint and immune system diseases — across the United States. Exagen makes money by billing insurance companies and patients for each test performed, meaning revenue depends on how many tests doctors order. The company operates entirely in the U.S. and is relatively small, with a market cap around $200 million. Its focus on a narrow but underserved area of autoimmune diagnostics gives it some specialization, but the negative operating and return margins show it is still spending more than it earns. The key challenge ahead is scaling test volume fast enough to reach profitability before cash resources run thin.