MS Bio Up 99% on Debut, Trading Value Nearly 2x Market Cap

Seoul — As of about 1:30 p.m. on Oct. 22, 2026, KOSPI is down 3.31% and KOSDAQ (the tech- and small-cap-heavy market) is down 2.67%, yet three stocks are up more than 20%. Only SKAI's move traces to a filing; MS Bio and BigWave Robotics rest on news reports and expectations. We will update this article with closing figures after the market closes.

Key points - KOSPI 5,545.84 (-3.31%), KOSDAQ 771.62 (-2.67%), both intraday. - Three stocks are up 20% or more, with combined trading value of about 949.9 billion won. - MS Bio's trading value of 821.8 billion won is about 1.9 times its market cap of 423.3 billion won. - Foreign investors and institutions were both net buyers of SKAI intraday (News1 Pim, i.e. Newspim). They had been net sellers for the prior three sessions.

At a glance

MS Bio (0013Y0): up 99% on debut day, with no filing

MS Bio listed on KOSDAQ today and is trading at 15,560 won, up 99.49% at 1:30 p.m. It is a first trading day, so there is no prior close; reports quote the gain against the offering price. One outlet reported it as high as the 130% range intraday (Business Post, 10:43), so the stock has given back about 30 percentage points. It is described as a regenerative-medicine company.

The company has filed nothing that explains the rise, and the coverage is limited to debut-day strength. Trading value is 821.8 billion won against a market cap of 423.3 billion won, about 1.9 times. At 12:35 p.m., 45.17 million shares had changed hands (Seoul Shinmun).

Two things to watch: whether trading value holds tomorrow, and when institutional lock-up shares are released and how many shares are free to trade. Since the stock is already well off its intraday high, where it closes will matter.

SKAI (357880): limit-up on share acquisition and convertible bond filings

SKAI is at 1,851 won, up 29.99%, the 30% daily limit. According to DART (Korea's official disclosure system), the company filed three material-event reports on Oct. 21: a convertible bond issuance decision (receipt no. 20261021000407), a decision to acquire shares in another company (20261021000417) and a decision to issue debt securities recognized as equity (20261021000411). Reports say the acquisition is of Sky Intelligence shares for 25.35 billion won and the perpetual convertible bond is 22.8 billion won (Data Investment, Oct. 21, 5:33-5:54 p.m.). The acquisition is about 25% of the current market cap of 102.6 billion won, and the bond is about 22%, so these are not small relative to the company.

But the titles and reports are as far as we can confirm. The purpose of the acquisition and the conversion terms are not clear. Convertible bonds can increase the share count, so this is not purely good news. On Oct. 21 the stock rose only 4.08% even with reports that SKAI took part in a global white paper with Nvidia and ABB Robotics (Robot Newspaper, ZDNet Korea). Today's move looks like the first session's reaction to the after-hours filings. The stock is still below its Sept. 23 close of 1,942 won.

Two things to check: how much the acquired business adds to SKAI's sales, and where the conversion price sits relative to the current price. Whether foreign and institutional buying continues after three sessions of selling is also worth watching.

BigWave Robotics (0035S0): third day up, but no new news today

BigWave Robotics is at 25,000 won, up 20.19% at 1:30 p.m. The stock rose 14% yesterday on the launch of its "Hyper Foundry" physical-AI development platform (Chosunbiz, Kumgang Ilbo), and today's gain comes with no fresh news. It is up 80.4% over five sessions. But this follows a slide of almost 64% from the post-listing closing high of 38,850 won on Sept. 30 to 13,860 won on Oct. 15, so the stock has not recovered its early post-listing level. It has been listed for 16 trading days.

Company filings in the past week are an extraordinary shareholders' meeting call and record-date notice on Oct. 20, plus an executive shareholding report. No filing confirms that the platform launch has turned into sales or a contract. Over the last two days foreign investors and institutions were net sellers (foreign -70,762 and -29,336 shares; institutions -35,504 and -73,940 shares on Oct. 20 and 21) while individuals bought.

First, whether the company files anything showing the platform has produced contracts or sales. Second, whether institutional and foreign selling eases while individual buying continues.