South Korean listed companies valued at over 1 trillion won ($940.7 million) have increased about 20 percent over the past year, largely driven by a recent boom in bio shares, data showed Sunday.

According to the data by Korea Exchange, there were 220 listed companies with market capitalization over 1 trillion won as of end-March, an increase from 187 a year ago.

A company with 1 trillion won in market capitalization, an equivalent to the "billion dollar club" in the United States, is regarded as a large cap in South Korea.

The benchmark KOSPI has 180 big caps, including the heaviest Samsung Electronics Co. valued at 315.9 trillion won, accounting for 19.8 percent of the 907 listed firms' total. The secondary KOSDAQ has 40 such heavyweights, or 3.1 percent of the total.

Compared with 10 years ago, the number of the 1 trillion-won club members has surged 70.5 percent, or 91, from 129 firms.

Pharmaceutical and bio shares led the increase over the decade.

In 2018, 23 biopharmaceutical companies were among the top-tier shares, sharply up from four in 2008.

Among the bio shares, drugmaker Celltrion Inc. was at the top, with a market cap of 38 trillion won, followed by Samsung Biologics Co. with 32 trillion won, Celltrion Healthcare with 14.6 trillion won and Sillajen Inc. with 7.3 trillion won. (Yonhap)