Stocks generally climbed Monday, as investors saw the path of least resistance as up. As the level of merger and acquisition activity rises, investors are increasingly targeting stocks they think have buyout potential, especially now that earnings season is over and it's easier to focus on more speculative factors in moving share prices. Yet several stocks moved sharply lower today despite the generally favorable mood on Wall Street, and AstraZeneca (NASDAQ:AZN), LifeLock (NYSE:LOCK), and Intercept Pharmaceuticals (NASDAQ:ICPT) were some of the worst performers on the day.

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AstraZeneca dropped 12% as shareholders finally came to grips with the idea that company management will not accept a buyout bid from Pfizer under just about any reasonable terms. Even a big boost of around 10% to $117 billion wasn't enough to get AstraZeneca to agree to a merger, with the company once again saying that the bid underestimates the true value of the company. Certainly, given the tax benefits available from moving to Great Britain from the U.S., AstraZeneca has the upper hand in any negotiations of a purchase price. Yet AstraZeneca shareholders clearly believe that there's no further room for negotiation, and the message they're sending the company today is that they'd prefer to take the best offer yet rather than rolling the dice and going it solo for the foreseeable future.

LifeLock plunged 18% after the specialist in cybersecurity and identity-theft protection said that some of the parts of its Wallet mobile application didn't comply fully with security standards governing credit and debit cards. As a result, LifeLock removed the App from various distribution stores. Given the importance of maintaining a solid reputation for the highest standards of cybersecurity, LifeLock's move was likely necessary in the long run, but it nevertheless could lead some would-be customers to think twice before trusting their financial information to the company.

Intercept Pharmaceuticals fell 7%, giving back most of the ground the small biotech got last week after getting positive comments from a couple of analysts. As with most developmental-stage biotech and pharmaceutical companies, investors have to endure long periods of waiting and speculation between reports on clinical trials, and it appears that Intercept's turn to wow investors might come in July if the company can release more data from its phase 2 study of obeticholic acid for treatment of nonalcoholic steatohepatitis. Until then, though, the volatile stock is likely to move at the faintest hint of news, and as frustrating as it is for investors, the upward and downward swings in Intercept shares don't always have fundamental news to justify them.

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