Who has been buying Seojin System stock?

8 distinct insiders have filed 2 disclosed insider purchases in Seojin System (178320), most recently on 2026-07-10. Each filer, their role, the number of shares and the price at filing are listed in the table on this page.

How many insider filings does Seojin System have?

Seojin System has 2 buy-side and 15 sell-side disclosures on record, covering ₩3.2B ($2.2M) in total reported value, spanning 2024-04-30 to 2026-07-10.

Where does StockDrifts get Seojin System insider data?

From DART D001/D002 insider disclosures — the official filing system run by the Financial Supervisory Service (Korea). StockDrifts parses each disclosure and matches it to daily price history; the original filings remain available directly from DART.

Do insider buys in Korean stocks predict returns?

Not uniformly. StockDrifts analysed 170,720 share-count changes across 56,930 Korean DART filings using cross-sectional alpha at fixed forward horizons, and found returns concentrated in particular signal tiers rather than in insider buying generally.

Seojin System 178320

Company

서진시스템Seojin System

Insiders

Buys

Total Value

₩3.2B ($2.2M)

Avg Return

-0.55%

Last Filing

2026-07-10

Seojin System (178320) has 2 disclosed insider purchases and 15 disclosed disposals on record, filed by 8 distinct insiders. Together those filings cover ₩3.2B ($2.2M) in reported transaction value. The earliest filing StockDrifts holds for Seojin System is dated 2024-04-30; the most recent is 2026-07-10. All of it is parsed from DART D001/D002 insider disclosures, the official disclosure system operated by the Financial Supervisory Service (Korea). Across these filings the average return since disclosure is -0.55%, measured from each filing date to the latest available close.

Price & insider activity (12 months)

Recent insider trades

Date	Type	Source	Insider	Position	Shares	Price at filing	Return	Value
2026-07-10	SELL	장외매도	전동규 Jeon Dong-gyu	CEO	-2.5M	₩47,350	+17.0%	₩129.3B ($89.8M)
2026-05-06	SELL	Market Sell	고용호 Go Yong-ho	Managing Director	-12.2K	₩59,500	-12.9%	₩725M ($504K)
2026-05-06	SELL	Market Sell	조홍일 Jo Hong-il	Managing Director	-6.7K	₩59,500	-12.9%	₩399M ($277K)
2026-05-06	SELL	Market Sell	김성철 Seongcheol Kim	Managing Director	-6.9K	₩59,500	-12.9%	₩410M ($285K)
2026-05-04	SELL	Market Sell	고용호 Go Yong-ho	Managing Director	-4.5K	₩61,300	-9.5%	₩275M ($191K)
2026-05-04	SELL	Market Sell	정종기 Jeong Jong-gi	vice president	-12.0K	₩61,300	-9.5%	₩736M ($511K)
2026-05-04	SELL	Market Sell	황봉주 Hwang Bong-ju	Managing Director	-5.0K	₩61,300	-9.5%	₩307M ($213K)
2026-05-04	SELL	Market Sell	이홍재 Hongjae Lee	Managing Director	-1.8K	₩61,300	-9.5%	₩110M ($77K)
2026-04-07	BUY	PROGRAM	정종기 Jeong Jong-gi	vice president	12.0K	₩42,600	+22.1%	₩511M ($355K)
2026-04-07	BUY	PROGRAM	조홍일 Jo Hong-il	Managing Director	6.0K	₩42,600	+22.1%	₩256M ($178K)
2026-04-07	BUY	주식매수선택권	황봉주 Hwang Bong-ju	Managing Director	6.0K	₩42,600	+22.1%	₩256M ($178K)
2026-04-07	BUY	PROGRAM	김성철 Seongcheol Kim	Managing Director	6.0K	₩42,600	+22.1%	₩256M ($178K)
2026-04-07	BUY	PROGRAM	이충우 Choongwoo Lee	president	12.0K	₩42,600	+22.1%	₩511M ($355K)
2026-04-07	BUY	PROGRAM	이홍재 Hongjae Lee	Managing Director	1.8K	₩42,600	+22.1%	₩77M ($53K)
2026-04-07	BUY	PROGRAM	고용호 Go Yong-ho	Managing Director	4.2K	₩42,600	+22.1%	₩179M ($124K)
2026-04-06	BUY	신규선임	황봉주 Hwang Bong-ju	Managing Director	5.0K	₩45,750	+13.7%	₩230M ($159K)
2026-03-26	SELL	전환등	전동규 Jeon Dong-gyu	CEO	-102.1K	₩46,300	-12.3%	₩4.7B ($3.3M)
2026-03-26	BUY	전환사채의권리행사	전동규 Jeon Dong-gyu	CEO	102.1K	₩46,300	+12.3%	₩4.7B ($3.3M)
2026-03-23	SELL	Market Sell	조홍일 Jo Hong-il	Managing Director	-7.3K	-	-	-
2026-03-23	SELL	Market Sell	이영대 Youngdae Lee	Internal director	-55.0K	-	-	-
2026-03-20	SELL	Market Sell	이영대 Youngdae Lee	Internal director	-40.0K	-	-	-
2026-03-20	SELL	Market Sell	조홍일 Jo Hong-il	Managing Director	-17.6K	-	-	-
2026-03-19	SELL	Market Sell	정종기 Jeong Jong-gi	vice president	-42.0K	-	-	-
2026-03-19	SELL	Market Sell	조홍일 Jo Hong-il	Managing Director	-11.9K	-	-	-
2026-03-19	SELL	Market Sell	이영대 Youngdae Lee	Internal director	-10.0K	-	-	-
2026-03-18	SELL	Market Sell	정종기 Jeong Jong-gi	vice president	-5.7K	-	-	-
2026-02-26	SELL	장외매도	전동규 Jeon Dong-gyu	CEO	-1.0M	-	-	-
2026-02-10	BUY	Market Buy	오동근 Oh Dong-geun	vice president	5.0K	₩34,400	+3.3%	₩172M ($119K)
2026-02-03	BUY	주식매수선택권	이영대 Youngdae Lee	Internal director	40.0K	₩36,450	-2.5%	₩1.5B ($1.0M)
2026-02-03	BUY	주식매수선택권	이영대 Youngdae Lee	Internal director	84.0K	₩36,450	-2.5%	₩3.1B ($2.1M)
2026-02-03	BUY	주식매수선택권	이충우 Choongwoo Lee	president	18.0K	₩36,450	-2.5%	₩656M ($456K)
2025-12-23	BUY	기타	전동규 Jeon Dong-gyu	CEO	102.1K	₩25,550	+39.1%	₩2.6B ($1.8M)
2025-03-10	BUY	Market Buy	정종기 Jeong Jong-gi	vice president	4.6K	₩21,100	+68.5%	₩97M ($67K)
2024-10-30	BUY	기타	전동규 Jeon Dong-gyu	CEO	240.0K	₩27,900	+27.4%	₩6.7B ($4.7M)
2024-09-25	SELL	전환등	전동규 Jeon Dong-gyu	CEO	-127.7K	₩26,350	-34.9%	₩3.4B ($2.3M)
2024-09-25	BUY	전환사채의권리행사	전동규 Jeon Dong-gyu	CEO	127.7K	₩26,350	+34.9%	₩3.4B ($2.3M)
2024-09-24	BUY	기타	전동규 Jeon Dong-gyu	CEO	127.7K	₩27,150	+30.9%	₩3.5B ($2.4M)
2024-08-26	SELL	시간외매매	전동규 Jeon Dong-gyu	CEO	-180.0K	₩25,850	-37.5%	₩4.7B ($3.2M)
2024-08-14	BUY	주식매수청구권 행사	정상수 normal number	vice president	60.0K	₩27,450	+29.5%	₩1.6B ($1.1M)
2024-08-14	BUY	주식매수청구권 행사	이영대 Youngdae Lee	Internal director	60.0K	₩27,450	+29.5%	₩1.6B ($1.1M)
2024-07-05	BUY	PROGRAM	조홍일 Jo Hong-il	Managing Director	488	₩31,850	+11.6%	₩16M ($11K)
2024-07-05	BUY	PROGRAM	이영대 Youngdae Lee	president	1.1K	₩31,850	+11.6%	₩34M ($24K)
2024-07-05	BUY	PROGRAM	정상수 normal number	vice president	876	₩31,850	+11.6%	₩28M ($19K)
2024-07-05	BUY	PROGRAM	이충우 Choongwoo Lee	Managing Director	1.0K	₩31,850	+11.6%	₩33M ($23K)
2024-07-05	BUY	PROGRAM	고용호 Go Yong-ho	Managing Director	284	-	-	-
2024-07-05	BUY	PROGRAM	정종기 Jeong Jong-gi	Managing Director	1.1K	₩31,850	+11.6%	₩34M ($24K)
2024-07-05	BUY	PROGRAM	김성철 Seongcheol Kim	Managing Director	890	₩31,850	+11.6%	₩28M ($20K)
2024-05-17	SELL	대여	전동규 Jeon Dong-gyu	CEO	-240.0K	₩25,200	-41.1%	₩6.0B ($4.2M)
2024-04-30	BUY	전환사채의권리행사	전동규 Jeon Dong-gyu	CEO	851.1K	₩24,700	+43.9%	₩21.0B ($14.6M)
2024-04-30	BUY	전환사채의권리행사	전동규 Jeon Dong-gyu	CEO	2.1M	₩24,700	+43.9%	₩51.1B ($35.5M)

Showing the 50 most recent of 52 filings.

Frequently asked questions

Who has been buying Seojin System stock?: 8 distinct insiders have filed 2 disclosed insider purchases in Seojin System (178320), most recently on 2026-07-10. Each filer, their role, the number of shares and the price at filing are listed in the table on this page.
How many insider filings does Seojin System have?: Seojin System has 2 buy-side and 15 sell-side disclosures on record, covering ₩3.2B ($2.2M) in total reported value, spanning 2024-04-30 to 2026-07-10.
Where does StockDrifts get Seojin System insider data?: From DART D001/D002 insider disclosures — the official filing system run by the Financial Supervisory Service (Korea). StockDrifts parses each disclosure and matches it to daily price history; the original filings remain available directly from DART.
Do insider buys in Korean stocks predict returns?: Not uniformly. StockDrifts analysed 170,720 share-count changes across 56,930 Korean DART filings using cross-sectional alpha at fixed forward horizons, and found returns concentrated in particular signal tiers rather than in insider buying generally.

Source filings

Every trade listed above is disclosed in DART D001/D002 insider disclosures, filed with the Financial Supervisory Service (Korea). View the original DART filings for Seojin System. For how StockDrifts scores these disclosures, see the Korea insider signal tier research, or browse every Korean stock we track.