What's up at Arca Biopharma? Analysts have been scratching their heads trying to figure out why, after the developer announced a new patent on Friday--hardly earthshattering news--its stock would go up more than 200 percent. TheStreet's Adam Feuerstein suggests it could be the result of momentum trading, with a higher price building steam. Ironically, he adds, Arca disclosed that it still hasn't reached agreement with the FDA on its special protocol assessment for the new Phase III the agency demanded on bucindolol. And that's the kind of news that normally wouldn't excite investors. Report