Who has been buying Y Biologics stock?

2 distinct insiders have filed 11 disclosed insider purchases in Y Biologics (338840), most recently on 2026-07-01. 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 Y Biologics have?

Y Biologics has 11 buy-side and 0 sell-side disclosures on record, covering ₩260M ($180K) in total reported value, spanning 2024-11-04 to 2026-07-01.

Where does StockDrifts get Y Biologics 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.

Y Biologics 338840

Company

와이바이오로직스Y Biologics

Insiders

Buys

Total Value

₩260M ($180K)

Avg Return

+29.37%

Last Filing

2026-07-01

Y Biologics (338840) has 11 disclosed insider purchases and 0 disclosed disposals on record, filed by 2 distinct insiders. Together those filings cover ₩260M ($180K) in reported transaction value. The earliest filing StockDrifts holds for Y Biologics is dated 2024-11-04; the most recent is 2026-07-01. 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 +29.37%, 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
2026-08-04	BUY	Market Buy	박영우 Youngwoo Park	CEO	3.1K	₩10,170	-1.1%	₩24M ($17K)
2026-07-31	BUY	Market Buy	박영우 Youngwoo Park	CEO	1.8K	₩8,180	+24.3%	₩14M ($10K)
2026-07-23	BUY	Market Buy	박영우 Youngwoo Park	CEO	2.0K	₩9,590	-2.7%	₩18M ($13K)
2026-07-01	BUY	Market Buy	박영우 Youngwoo Park	CEO	890	₩12,550	-6.5%	₩11M ($8K)
2026-06-30	BUY	Market Buy	박영우 Youngwoo Park	CEO	7.4K	₩12,000	-2.2%	₩89M ($62K)
2026-06-26	BUY	Market Buy	박영우 Youngwoo Park	CEO	2.0K	₩10,910	+7.6%	₩22M ($15K)
2026-06-25	BUY	Market Buy	박영우 Youngwoo Park	CEO	1.8K	₩11,910	-1.4%	₩21M ($15K)
2026-06-23	BUY	Market Buy	박영우 Youngwoo Park	CEO	1.9K	₩11,850	-7.9%	₩23M ($16K)
2026-06-17	BUY	Market Buy	박영우 Youngwoo Park	CEO	1.5K	₩15,590	-14.9%	₩23M ($16K)
2026-06-10	BUY	Market Buy	박영우 Youngwoo Park	CEO	1.5K	₩13,100	+9.8%	₩20M ($14K)
2026-06-04	BUY	Market Buy	박영우 Youngwoo Park	CEO	1.3K	₩15,330	-3.1%	₩20M ($14K)
2026-04-09	BUY	주식매수선택권	장우익 Jang Woo-ik	CEO	60.0K	₩24,900	-3.4%	₩1.5B ($1.0M)
2026-03-17	SELL	시간외매매	박범찬 Beomchan Park	vice president	-20.0K	-	-	-
2025-12-22	SELL	장외매도	장우익 Jang Woo-ik	CEO	-20.0K	₩23,950	-9.6%	₩479M ($333K)
2025-12-11	BUY	주식매수선택권	이상헌 Lee Sang-heon	Managing Director	26.0K	₩25,950	+1.2%	₩675M ($469K)
2025-12-11	BUY	주식매수선택권	장명자 Jang Myeong-ja	moving	6.0K	₩25,950	+1.2%	₩156M ($108K)
2025-12-11	BUY	주식매수청구권 행사	박범찬 Beomchan Park	vice president	20.0K	₩25,950	+1.2%	₩519M ($360K)
2025-12-11	BUY	주식매수선택권	장우익 Jang Woo-ik	CEO	20.0K	₩25,950	+1.2%	₩519M ($360K)
2025-09-29	BUY	Market Buy	윤주한 Yoon Joo-han	Director of Antibody New Drug Research Institute	72	₩14,220	+84.6%	₩1M ($711)
2025-08-05	BUY	Market Buy	윤주한 Yoon Joo-han	Director of Antibody New Drug Research Institute	453	₩10,760	+144.0%	₩5M ($3K)
2025-07-18	BUY	Market Buy	윤주한 Yoon Joo-han	Director of Antibody New Drug Research Institute	2.0K	₩12,320	+113.1%	₩25M ($17K)
2025-05-27	SELL	전환등	박영우 Youngwoo Park	CEO	-25.0K	₩11,190	-134.6%	₩280M ($194K)
2025-05-27	BUY	행사가액조정	박영우 Youngwoo Park	CEO	27.8K	₩11,190	+134.6%	₩311M ($216K)
2024-11-04	BUY	주식매수선택권	장명자 Jang Myeong-ja	moving	10.0K	₩11,420	+129.9%	₩114M ($79K)

Frequently asked questions

Who has been buying Y Biologics stock?: 2 distinct insiders have filed 11 disclosed insider purchases in Y Biologics (338840), most recently on 2026-07-01. 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 Y Biologics have?: Y Biologics has 11 buy-side and 0 sell-side disclosures on record, covering ₩260M ($180K) in total reported value, spanning 2024-11-04 to 2026-07-01.
Where does StockDrifts get Y Biologics 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 Y Biologics. For how StockDrifts scores these disclosures, see the Korea insider signal tier research, or browse every Korean stock we track.