The upturn came after their roller-coaster trading in recent months. According to the bourse operator, Korea Exchange, its healthcare index, which is comprised of 77 major bio shares traded on the main KOSPI and secondary KOSDAQ markets, hit a yearly high on April 11 but tumbled more than 25 percent on July 25 to fall to a record low for this year.

Since last year, bio shares have drawn keen attention from investors, as the country's healthcare industry has emerged as a major item for export on the back of local entities' successful commercialization of new drugs and their constant investment in research and development.

In recent months, however, the shares have been under downward pressure to experience serious correction after some analysts argued that their investments seem overvalued while clinical outcomes fell short of expectations.

"We conclude that most late-stage pharma company R&D pipeline assets are likely over-valued and that below-expectations clinical outcomes and commercial success will normalize valuations over time," Goldman Sachs said in its latest analytic report.

Investors have also been reluctant to expand their holdings while facing some negative issues involving major players, such as alleged accounting fraud by Samsung Biologics and the detention of the chief of Naturecell Co. for suspected manipulation of its stock shares.

Experts pointed to the Financial Supervisory Service's looking into pharmaceuticals' accounting rules regarding their R&D expenses as a reason for weak investor sentiment.

"But now with some uncertainties having been eased and positive signs of their business activities, investors are expected to pick up bio bargains," Jin Hong-guk, an expert at Korea Investment & Securities, said.

Earlier this month, Samsung Group vowed to invest 180 trillion won over the next three years, with some 25 trillion won being projected to go toward the growth of the bio sector.

Investors, moreover, found a source of relief from comments by Kim Yong-beom, vice chief of the Financial Services Commission, on Thursday.

Attending a business forum, Kim hinted at relaxing accounting regulations for local pharmaceuticals' R&D expenditures by saying that it could be "somewhat harsh" to call on local firms to abide by the same accounting practices of global pharmaceuticals in advanced countries.

"After hitting rock bottom in the second quarter, bio shares are forecast to rebound on high hopes for their solid growth," Seon Min-jeong of Hana Financial Investment said. (Yonhap)