Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Idenix (Nasdaq: IDIX) surged more than 11% in early trading before closing up 4.7% for the day. A William Blair analyst named the company as a likely buyout candidate while upgrading the stock to "outperform" from "market perform" in a new report.

So what: Idenix and Inhibitex (Nasdaq: INHX) each rallied on the report, in which analyst Y. Katherine Xu said the market for hepatitis C treatments would expand rapidly before peaking at $18 billion by 2024. Both companies compete with Pharmasset (Nasdaq: VRUS) in developing hepatitis C drugs.

Now what: Xu has a point. Last week, Gilead Sciences (Nasdaq: GILD) announced plans to acquire Pharmasset for $11 billion. Of the two, only Inhibitex commands more than $1 billion in market value as of this writing. Would either company command as much as Pharmasset in a buyout? Please weigh in using the comments box below.

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