Even against the backdrop of last week's staggering market slide, the dive of Oxford Health Plans' stock was spectacular. Oxford, long considered the healthiest managed-care organization in the U.S. and the envy of the industry, went into cardiac arrest when an unexpectedly poor earnings forecast sent its stock crashing more than 62%, from $68 to $26--the worst performance in a day that saw some beauts.
What went wrong? Just about everything. Three days earlier, the Connecticut-based HMO discovered that it was hemorrhaging money through a computer glitch that had caused the company to overestimate its membership enrollment and miscalculate the costs...