The combined market capitalization of Korea's publicly listed companies crossed 1.2 trillion U.S. dollars as of the end of last week.
Citing Bloomberg data, Yonhap News reports that Korea took one step back from last year, when its market was the eleventh biggest in the world.
Analysts say capital is flowing to other emerging economies in the Southeast Asian region especially to India, where new Prime Minister Narendra Modi is pledging sweeping economic reforms.
Thanks to his so-called 'Modinomics', India's benchmark Sensex has jumped 19 percent so far this year with the total market value surging nearly 30 percent.
Korea's main index, the KOSPI edged down one percent this year.
And although total market capitalization went up by 4 percent, the actual increase will be lower because of the strengthening won.
The Korean market currently makes up 1.9 percent of the global market.
That's down zero.1 percentage points from last month and down zero.4 percentage points from August 2011, when it was at its highest.
Experts say foreign buyers are moving their money away from Korea because they feel that Samsung Electronics, the major player on the KOSPI, is not pushing for growth as strongly as they could.
Another reason is said to be the weaker-than-expected performances by Korea's usual strongholds -- the shipbuilding and petrochemical industries, which rely heavily on exports to China.
Laah Hyun-kyung, Arirang News.