More than 3 million retail investors hold penny stocks and low-market-cap shares that could be at risk of delisting as Korea tightens listing requirements, data showed Sunday. Their holdings were valued at nearly 8 trillion won ($5.9 billion). A total of 238 companies on the benchmark KOSPI and secondary Kosdaq either traded below 1,000 won a share or failed to meet minimum market capitalization requirements, according to the Korea Exchange. Of those, 61 were listed on the KOSPI and 177 on the Kosdaq, meaning the number of affected Kosdaq companies was nearly three times higher. These companies had a combined 3,126,710 retail shareholders, with their holdings valued at 7.85 trillion won, based on their latest annual reports, according to Rep. Park Min-kyu of the ruling Democratic Party of Korea, who obtained and released the data. The tally may include duplication because one investor can own shares in multiple companies, Park said. Korean financial authorities earlier this year announced tougher delisting rules aimed at improving the quality of listed companies and restoring investor c