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 medical cost containment and managed care services provider CorVel (Nasdaq: CRVL) tanked by as much as 12% earlier in the trading day after Copperfield Research issued a report questioning the company's ethical and legal practices.

So what: Copperfield, which admittedly has a short position in CorVel, likened the potential accusations of wrongdoing at CorVel to the investigations currently under way at Community Health Systems (NYSE: CYH). Copperfield notes that CorVel has purportedly been operating as a silent preferred provider prganization, which has allowed it to regularly undercut payments to health-care providers.

Now what: Here we go with another case of questionable ethics, potentially on both sides of the coin. It's always hard to believe a research firm like Copperfield, which has a vested interest in the outcome of this story and is unwilling to accuse CorVel of any wrongdoing -- it's only willing to insinuate it. On the other hand, this also puts a dark cloud over CorVel's business practices until the company refutes these allegations. I personally feel the stock is worth avoiding altogether, but it may be worth keeping a close eye on.

Craving more input? Start by adding CorVel to your free and personalized watchlist so you can keep up on the latest news with the company.