Ebb & Flow
Efficient markets?By Eric Pierce
Staff writer
If a stock doubles over the course of a year, conventional Wall Street wisdom would conclude that the company was obviously under-valued. But if investors whack 23 percent off a $957 million market cap when an FDA panel recommends approval for a niche product, was the company obviously over-valued?

Investors removed $230 million from Gilead's valuation on Friday as word of the company's FDA panel hearing on Vistide filtered out. Despite the panel's ultimate recommendation to approve the drug, GILD closed down $8.25 at $26.50. GILD's market cap is down to $736 million from a recent high of about $1 billion, but still is almost double its valuation this time last year.

Some analysts have been saying that the CMV retinitis indication for Vistide is too small to justify GILD's valuation. Recent reports from Eric Hecht at Morgan Stanley anticipated "modestly successful" Vistide sales in the $50-$75 million range. Tom Dietz from