Investors have had a pessimistic attitude about the stock market nearly all year, with advances inevitably giving way to declines. But stocks proved their resiliency today, as broad-market indexes regained their footing even after plunging to substantial declines in midday trading. With major markets posting gains of a quarter-percent to a half-percent, though, the jumps in Twitter (TWTR), Trina Solar (NYSE: TSL), and Benefitfocus (BNFT) were much more noteworthy and came on company-specific news that heartened shareholders.

Twitter soared 11% after several positive developments for the social-media company. Of primary importance were reports that indicated that major institutional investors in Twitter plan not to sell their shares even when Twitter's lockup period ends early next month. With the potential for insiders and large investors to sell nearly 475 million Twitter shares once the lockup expires, ordinary investors were nervous about the possible share-price decline resulting from massive selling pressure. Yet with the Wall Street Journal having found that holders of about a third of Twitter's shares won't sell next month, the stock bounced higher. The hiring of a key competitor's mapping-software executive and Twitter's purchase of data-analytics company Gnip also raised optimism about the rising social-media star.

Trina Solar rose 6%, regaining almost all of the ground it lost Monday when it announced that its first-quarter shipment volumes would miss previous guidance. At first glance a plunge of 130 megawatts was extremely scary, especially as it marked about a fifth of its total module-shipment volume for the quarter. Yet shareholders apparently reconsidered and took solace in the fact that Trina reiterated its full-year shipment guidance, arguing that it fully expects that shipments to the European Union will resume normal levels as soon as Trina can agree on minimum-import prices under new trade rules. Moreover, with expected boosts in gross margins, Trina could well remain profitable this quarter, giving the company another victory compared to more troubled times in the recent past.

Benefitfocus jumped 8% after the cloud-based human resources services provider announced that it had brought on a major new client. Propane company AmeriGas (APU) picked Benefitfocus to help AmeriGas administer benefits for its workforce of nearly 9,000 employees, including benefits enrollment and communication services. Given the extensive network that AmeriGas has, spanning 1,200 locations throughout the nation, a cloud-based solution is almost a necessity. Yet by choosing Benefitfocus for a multi-year agreement, AmeriGas gave its vote of confidence that the upstart cloud-software provider can meet its HR needs, and that's a valuable commodity in an industry full of similar up-and-coming cloud HR providers.