Who has been buying Korea Optical Communication stock?

3 distinct insiders have filed 1 disclosed insider purchases in Korea Optical Communication (010170), most recently on 2026-07-13. 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 Korea Optical Communication have?

Korea Optical Communication has 1 buy-side and 7 sell-side disclosures on record, covering ₩22.7B ($15.7M) in total reported value, spanning 2001-12-15 to 2026-07-13.

Where does StockDrifts get Korea Optical Communication 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.

Korea Optical Communication 010170

Company

대한광통신Korea Optical Communication

Insiders

Buys

Total Value

₩22.7B ($15.7M)

Avg Return

+33.59%

Last Filing

2026-07-13

Korea Optical Communication (010170) has 1 disclosed insider purchases and 7 disclosed disposals on record, filed by 3 distinct insiders. Together those filings cover ₩22.7B ($15.7M) in reported transaction value. The earliest filing StockDrifts holds for Korea Optical Communication is dated 2001-12-15; the most recent is 2026-07-13. 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 +33.59%, 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
2026-07-13	SELL	Market Sell	설윤석 Seol Yun-seok	CEO	-357.6K	₩10,910	+5.6%	₩3.9B ($2.7M)
2026-07-03	SELL	Market Sell	티에프오인더스트리 TFO Industries	-	-34.4K	₩12,240	+13.0%	₩421M ($293K)
2026-07-02	SELL	Market Sell	티에프오인더스트리 TFO Industries	-	-590.4K	₩11,960	+10.9%	₩7.1B ($4.9M)
2026-06-30	SELL	Market Sell	설윤성 Seol Yunseong	-	-664.9K	₩13,200	+19.3%	₩8.8B ($6.1M)
2026-06-29	SELL	Market Sell	티에프오인더스트리 TFO Industries	-	-512.0K	-	-	-
2026-06-26	SELL	Market Sell	티에프오인더스트리 TFO Industries	-	-250.0K	-	-	-
2026-06-25	SELL	Market Sell	티에프오인더스트리 TFO Industries	-	-250.0K	-	-	-
2026-03-09	SELL	기타	설윤석 Seol Yun-seok	CEO	-89.2K	₩4,245	-119.1%	₩379M ($263K)
2026-03-09	SELL	기타	티에프오인더스트리 TFO Industries	-	-591.9K	₩4,245	-119.1%	₩2.5B ($1.7M)
2026-03-09	SELL	기타	티에프오인더스트리 TFO Industries	-	-74.0K	₩4,245	-119.1%	₩314M ($218K)
2026-03-09	BUY	Market Buy	티에프오인더스트리 TFO Industries	-	591.9K	₩4,245	+119.1%	₩2.5B ($1.7M)
2026-03-09	BUY	유상신주취득	설윤석 Seol Yun-seok	CEO	713.3K	₩4,245	+119.1%	₩3.0B ($2.1M)
2026-03-09	SELL	기타	설윤석 Seol Yun-seok	CEO	-713.3K	₩4,245	-119.1%	₩3.0B ($2.1M)
2026-02-02	SELL	장외매도	설윤석 Seol Yun-seok	CEO	-761.9K	₩3,195	-191.1%	₩2.4B ($1.7M)
2026-02-02	SELL	장외매도	티에프오인더스트리 TFO Industries	-	-1.2M	₩3,195	-191.1%	₩4.0B ($2.8M)
2026-01-23	BUY	기타	티에프오인더스트리 TFO Industries	-	1.9M	₩2,995	+210.5%	₩5.7B ($4.0M)
2026-01-23	BUY	기타	설윤석 Seol Yun-seok	CEO	1.6M	₩2,995	+210.5%	₩4.7B ($3.3M)
2025-02-19	BUY	유상신주취득	설윤석 Seol Yun-seok	CEO	3.4M	₩814	+1042.5%	₩2.7B ($1.9M)
2006-05-12	BUY	무상신주취득	설윤성 Seol Yunseong	-	190.0K	-	-	-
2004-09-16	BUY	기타	설윤성 Seol Yunseong	-	475.0K	-	-	-
2004-09-16	SELL	기타	설윤성 Seol Yunseong	-	-475.0K	-	-	-
2001-12-15	BUY	무상신주취득	설윤성 Seol Yunseong	-	158.3K	-	-	-

Frequently asked questions

Who has been buying Korea Optical Communication stock?: 3 distinct insiders have filed 1 disclosed insider purchases in Korea Optical Communication (010170), most recently on 2026-07-13. 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 Korea Optical Communication have?: Korea Optical Communication has 1 buy-side and 7 sell-side disclosures on record, covering ₩22.7B ($15.7M) in total reported value, spanning 2001-12-15 to 2026-07-13.
Where does StockDrifts get Korea Optical Communication 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 Korea Optical Communication. For how StockDrifts scores these disclosures, see the Korea insider signal tier research, or browse every Korean stock we track.