Plito Hits Limit-Up as KOSDAQ Falls 3%; Unitechno Fades 21% to 5%

As of the Oct. 20, 2026 close (data as of 4:31 p.m. KST)

Key points

• KOSPI fell 3.73% to 5,552.74. KOSDAQ (tech- and small-cap-heavy market) fell 3.33% to 781.97.
• Three stocks rose on the day: Plito (+29.99%, the 30% daily limit), Bigwave Robotics (+22.24%) and Unitechno (+5.10%).
• Trading value was 131.4 billion won for Bigwave Robotics, 15.6 billion for Unitechno and 13.2 billion for Plito.
• Only Plito's rise is backed by a company filing. The other two rest on press reports.

Seoul — On a day when KOSDAQ fell more than 3%, Plito (300080) closed at the daily limit after a preliminary earnings filing showed nine-month operating profit of 10.3 billion won. Bigwave Robotics (0035S0) and Unitechno (241690) rose on reports with no filing on DART (Korea's official disclosure system), and Unitechno gave back most of an intraday gain: it was up 21% around 1:30 p.m. and closed up 5%.

At a glance

Plito (300080): a record operating profit filing, and the limit-up

Plito closed at 10,750 won, up 29.99%, the limit-up, after reporting record nine-month results. DART carried a preliminary consolidated earnings filing (fair disclosure) from the company on Oct. 20 (receipt no. 20261020900285). According to Newsis, cumulative revenue through the third quarter was 31.1 billion won and operating profit 10.3 billion won, more than all of last year's operating profit. Techworld put the increase at 89.7% from a year earlier, and Wide Economy reported that third-quarter operating profit alone rose 217%. The cumulative operating margin works out to about 33% (10.3 billion over 31.1 billion).

The stock is up 36.2% over two days and 36.6% over five sessions, with a market cap of 177.7 billion won. Foreign investors were net buyers for four straight sessions from Oct. 14 to 19, about 35,000 shares in total, while individuals were net sellers. It was up 28.42% at about 1:30 p.m. and reached the limit by the close. A separate voluntary filing on Oct. 15 reported selection for a government data-support program for a domestic AI foundation model project, but the stock fell 3.68% that day.

What the filing does not say matters too. Its title alone does not show whether one-off gains are mixed in, and the revenue and profit figures above come from press reports. To judge whether the rise lasts, check the quarterly report for where revenue came from (recurring data sales or a one-time item) and whether foreign net buying continues tomorrow.

Bigwave Robotics (0035S0): up 22% on a platform launch, with no filing

Bigwave Robotics closed at 18,410 won, up 22.24%, as reports spread that it had unveiled "Hyper Foundry," an integrated robot-AI development platform. Edaily, Robot Shinmun and AI Times reported the launch, and Wide Economy said the stock was strong on expectations of a humanoid demo. Pinpoint News said it was the only one rising on a day when physical-AI and humanoid stocks mostly fell. No filing has appeared on DART in the past seven days, so this is an expectation-driven move with no contract or earnings on the record.

The stock is on its 14th trading day since listing. It is 31.9% below its first-day close of 27,050 won and about 52.6% below its highest close of 38,850 won the next day. It fell to 13,860 won on Oct. 15, then rebounded 23.1% in two sessions. Trading value of 131.4 billion won was about 70% of its 189.1 billion won market cap. On Oct. 16, foreign investors were net buyers of about 117,000 shares while individuals sold about 104,000.

To judge whether this lasts, look at when the humanoid demo mentioned in the reports is actually held. Because the stock listed recently, the date when institutions' mandatory holding period ends and whether trading value stays above 100 billion won tomorrow are also worth checking.

Unitechno (241690): up 21% on an ESS supplier report, then pared to 5%

Unitechno closed at 2,680 won, up 5.10%, on reports that it was selected as a new supplier of next-generation ESS (energy storage system) parts for global battery maker "L" in North America. Newsis said the company announced this on the 20th. Yet at about 1:30 p.m. the stock was up 21.18% at 3,090 won, and Vegan News wrote that it "hit the limit and was pushed back." Most of the intraday gain disappeared. It is up 12.8% over five sessions on 15.6 billion won in trading value.

The reported amounts differ. Wide Economy and Christian Daily reported a 44 billion won order, while Youth Alliance wrote of an expected 11 billion won in annual revenue from 2028. The 44 billion figure is about 67% of the 65.6 billion won market cap. Against the 109 billion won 2025 revenue forecast in a November 2025 Korea IR Service report, 11 billion a year is about 10% and 44 billion about 40%. But no filing has appeared on DART in the past seven days, so company filings cannot settle which figure is right. Foreign investors were net buyers in each of the past five sessions, about 27,000 shares in total.

Whether the rise holds up depends on whether the company files the supply contract on DART, and whether the amount and term are 44 billion won or 11 billion a year. Also worth watching: whether trading value stays near today's 15.6 billion won tomorrow and where the stock finds support after fading intraday.

What happened to stocks we covered earlier

Changes are from the closing price at the time of each article to the Oct. 20 close. KOSDAQ fell 3.33% on the day, which should be kept in mind.

Seven of the eight fell. Among the six that had risen on reports alone, five fell and only Eco&Dream rose. Melcon, whose rise we could not explain, fell the most.