My definition of "failing" certainly doesn't include companies that are still profitable, employ hundreds of thousands of people worldwide, have hardware in every Fortune 500 company's datacenter, and is the market leader in some high-growth fields.

Thanks for reminding me how useful a site finance.yahoo is, if you take that graph back to 2005, IBM doesn't look that bad. You also see the precipitous fall Groupon had from its earliest days.

Consistently losing money without massive growth, or a ~50% and growing drop in both revenue and profits, or failing to diversify as their only revenue sources goes away.

PS: Notice how none of the above mention stock price, there is a reason for that.