Labcorp Holdings (LH) could be a solid choice for investors given its recent upgrade to a Zacks Rank #2 (Buy). This upgrade primarily reflects an upward trend in earnings estimates, which is one of the most powerful forces impacting stock prices. Fundamentally speaking, rising earnings estimates and the consequent rating upgrade for Labcorp imply an improvement in the company's underlying business. Investors should show their appreciation for this improving business trend by pushing the stock higher. Harnes ...