A beaten-down diagnostics stock is quietly tightening margins and drawing fresh institutional conviction—here’s what that means for long-term investors.On November 14, New York City-based Newtyn Management disclosed a purchase of 994,332 shares of QuidelOrtho Corporation (QDEL), increasing its stake by approximately $30.4 million.What HappenedAccording to a filing with the Securities and Exchange Commission dated November 14, Newtyn Management reported buying 994,332 additional shares of QuidelOrtho Corpora ...