Who has been buying JSTEC stock?

3 distinct insiders have filed 10 disclosed insider purchases in JSTEC (090470), most recently on 2026-06-12. 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 JSTEC have?

JSTEC has 10 buy-side and 1 sell-side disclosures on record, covering ₩904M ($628K) in total reported value, spanning 2018-02-23 to 2026-06-12.

Where does StockDrifts get JSTEC 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.

JSTEC 090470

Company

제이스텍JSTEC

Insiders

Buys

Total Value

₩904M ($628K)

Avg Return

+22.95%

Last Filing

2026-06-12

JSTEC (090470) has 10 disclosed insider purchases and 1 disclosed disposals on record, filed by 3 distinct insiders. Together those filings cover ₩904M ($628K) in reported transaction value. The earliest filing StockDrifts holds for JSTEC is dated 2018-02-23; the most recent is 2026-06-12. 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 +22.95%, 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
2026-06-12	BUY	PROGRAM	신용욱 Yongwook Shin	moving	100	-	-	-
2026-06-12	BUY	PROGRAM	신용욱 Yongwook Shin	moving	24	-	-	-
2026-06-10	BUY	PROGRAM	정재완 Jaewan Jeong	moving	1.8K	-	-	-
2026-06-10	BUY	PROGRAM	백일 100 days	moving	1.8K	-	-	-
2026-06-10	BUY	PROGRAM	최연민 Yeonmin Choi	moving	1.8K	-	-	-
2026-06-10	BUY	PROGRAM	안윤태 Yuntae Ahn	moving	1.8K	-	-	-
2026-06-10	BUY	PROGRAM	정문수 Moonsoo Jeong	moving	1.8K	-	-	-
2026-06-10	BUY	PROGRAM	윤석열 Yoon Seok-yeol	moving	1.8K	-	-	-
2026-06-10	BUY	PROGRAM	정영흠 Youngheum Jeong	moving	1.8K	-	-	-
2026-06-10	BUY	PROGRAM	김성환 Seonghwan Kim	Managing Director	2.3K	-	-	-
2026-06-10	BUY	PROGRAM	동영화 movie	vice president	2.7K	-	-	-
2026-06-10	BUY	PROGRAM	김진극 Kim Jin-geuk	vice president	2.7K	-	-	-
2026-06-10	BUY	PROGRAM	권영찬 Youngchan Kwon	vice president	5.1K	-	-	-
2026-06-10	BUY	PROGRAM	신용욱 Yongwook Shin	moving	1.8K	-	-	-
2026-06-10	BUY	PROGRAM	김상기 Kim Sang-ki	moving	1.8K	-	-	-
2026-06-10	BUY	PROGRAM	정대흠 Jeong Dae-heum	vice president	2.7K	-	-	-
2026-03-26	BUY	PROGRAM	장웅상 Woongsang Jang	independent director	6.0K	₩9,620	-0.8%	₩58M ($40K)
2026-01-01	BUY	신규선임	안윤태 Yuntae Ahn	moving	1.5K	₩5,100	+28.0%	₩8M ($5K)
2026-01-01	BUY	신규선임	정영흠 Youngheum Jeong	moving	170.0K	₩5,100	+28.0%	₩867M ($602K)
2025-04-10	BUY	PROGRAM	정대흠 Jeong Dae-heum	vice president	245	-	-	-
2025-02-14	BUY	Market Buy	정대흠 Jeong Dae-heum	vice president	15.0K	₩5,270	+23.9%	₩79M ($55K)
2025-02-13	BUY	Market Buy	정대흠 Jeong Dae-heum	vice president	17.3K	₩5,260	+24.1%	₩91M ($63K)
2025-02-12	BUY	Market Buy	정대흠 Jeong Dae-heum	vice president	12.7K	₩5,300	+23.2%	₩67M ($47K)
2025-02-10	BUY	Market Buy	정대흠 Jeong Dae-heum	vice president	47.0K	₩5,370	+21.6%	₩252M ($175K)
2024-12-17	BUY	Market Buy	정대흠 Jeong Dae-heum	vice president	11.0K	₩5,300	+23.2%	₩58M ($40K)
2024-12-16	BUY	Market Buy	정대흠 Jeong Dae-heum	vice president	9.0K	₩5,370	+21.6%	₩48M ($34K)
2024-12-13	BUY	Market Buy	정대흠 Jeong Dae-heum	vice president	58.0K	₩5,310	+23.0%	₩308M ($214K)
2018-02-23	SELL	Market Sell	동영화 movie	vice president	-360	-	-	-

Frequently asked questions

Who has been buying JSTEC stock?: 3 distinct insiders have filed 10 disclosed insider purchases in JSTEC (090470), most recently on 2026-06-12. 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 JSTEC have?: JSTEC has 10 buy-side and 1 sell-side disclosures on record, covering ₩904M ($628K) in total reported value, spanning 2018-02-23 to 2026-06-12.
Where does StockDrifts get JSTEC 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 JSTEC. For how StockDrifts scores these disclosures, see the Korea insider signal tier research, or browse every Korean stock we track.