Quest Diagnostics (DGX 5.62%) stock was teasing its all-time high on Thursday, no mean feat for a company that's been publicly traded for decades. The healthcare testing specialist's share price was up by more than 5% in late afternoon action, well ahead of the S&P 500 index's 0.8% gain at that point in the day. Notching a double beatThe main reason for the bullish move wasn't hard to figure out -- Quest posted its fourth-quarter and full-year 2024 results this morning. Investors were particularly impressed ...