Are you comparing these companies to their industry peers, or looking at them in isolation? The most useful starting points are the price-to-earnings ratio (P/E) - which tells you how many dollars investors are paying per dollar of profit - and price-to-book ratio (P/B) for asset-heavy businesses. You'll also want to check the PEG ratio if the company's growing fast, since a high P/E might make sense if earnings are climbing quickly. Beyond the numbers, look at debt levels, profit margins, and whether management is actually reinvesting gains or just burning cash; a cheap stock price often signals real problems, not a bargain. Most investors glance at a few of these metrics against competitors in the same sector rather than trying to pinpoint some "true value" - if everything looks worse than similar companies, that's usually the red flag you need.