GCTS

GCT Semiconductor Holding, Inc.

Insider trading activity for GCT Semiconductor Holding, Inc., straight from SEC Form 4 filings. Net figures below count open-market buys and sales only — grants, option exercises and tax withholding are excluded because they are compensation, not decisions to trade.

Past 3 months

net buying

Bought(0 · 0 insiders): $0
Sold(0 · 0 insiders): $0

Past 6 months

net buying

Bought(0 · 0 insiders): $0
Sold(0 · 0 insiders): $0

Past 12 months

+$58.1K

net buying

Bought(3 · 1 insiders): $58.1K
Sold(0 · 0 insiders): $0

Transaction history

The 60 most recent Form 4 transactions.

Open in screener →

Insider transactions, newest first: date, security, transaction type, size and a link to the filing each row came from.
Date	Insider	Role	Type	Shares	Price	Value	Δ Own	Filing
Sep 10	Kim Jeong-Min	Chief Technology Officer	AGRANT	100,000	—	—	+33.0%	Open the original filing on SEC.gov
Sep 10	Sum Alex	Sr. VP of Sales and…	AGRANT	75,000	—	—	+40.8%	Open the original filing on SEC.gov
Sep 10	Schlaefer John	President, CEO & Class…	AGRANT	150,000	—	—	+74.0%	Open the original filing on SEC.gov
Sep 10	Cheng Edmond	Chief Financial Officer	AGRANT	145,000	—	—	+96.0%	Open the original filing on SEC.gov
Jun 30	Lee Kyeongho	Director	AGRANT	9,259	—	—	+0.9%	Open the original filing on SEC.gov
Jun 30	Shin Hyunsoo	Director	AGRANT	9,259	—	—	+1.1%	Open the original filing on SEC.gov
Jun 30	Chun Kukjin	Director	AGRANT	9,259	—	—	+10.4%	Open the original filing on SEC.gov
Jun 30	Chan Nelson	Director	AGRANT	9,259	—	—	+7.4%	Open the original filing on SEC.gov
Jun 30	Barker Robert	Director	AGRANT	9,259	—	—	+6.5%	Open the original filing on SEC.gov
Jun 30	Tuder Jeffrey	Director	AGRANT	9,259	—	—	+6.5%	Open the original filing on SEC.gov
Mar 31	Tuder Jeffrey	Director	AGRANT	24,122	—	—	+20.5%	Open the original filing on SEC.gov
Mar 31	Lee Kyeongho	Director	AGRANT	24,122	—	—	+2.3%	Open the original filing on SEC.gov
Mar 31	Shin Hyunsoo	Director	AGRANT	24,122	—	—	+3.1%	Open the original filing on SEC.gov
Mar 31	Chun Kukjin	Director	AGRANT	24,122	—	—	+37.0%	Open the original filing on SEC.gov
Mar 31	Chan Nelson	Director	AGRANT	24,122	—	—	+23.8%	Open the original filing on SEC.gov
Mar 31	Barker Robert	Director	AGRANT	24,122	—	—	+20.4%	Open the original filing on SEC.gov
Feb 23	Chun Kukjin	Director	GGIFT	40,000	—	—	-38.0%	Open the original filing on SEC.gov
Dec 31, 2025	Tuder Jeffrey	Director	AGRANT	22,916	—	—	+24.1%	Open the original filing on SEC.gov
Dec 31, 2025	Lee Kyeongho	Director	AGRANT	22,916	—	—	+2.2%	Open the original filing on SEC.gov
Dec 31, 2025	Shin Hyunsoo	Director	AGRANT	22,916	—	—	+3.0%	Open the original filing on SEC.gov
Dec 31, 2025	Chun Kukjin	Director	AGRANT	22,916	—	—	+27.8%	Open the original filing on SEC.gov
Dec 31, 2025	Chan Nelson	Director	AGRANT	22,916	—	—	+29.1%	Open the original filing on SEC.gov
Dec 31, 2025	Barker Robert	Director	AGRANT	22,916	—	—	+24.0%	Open the original filing on SEC.gov
Nov 25, 2025	Shin Hyunsoo	Director	PBUY	16,725	$1.28	$21.4K	+2.3%	Open the original filing on SEC.gov
Nov 21, 2025	Shin Hyunsoo	Director	PBUY	3,180	$1.28	$4.1K	+0.4%	Open the original filing on SEC.gov
Nov 20, 2025	Shin Hyunsoo	Director	PBUY↓	25,453	$1.28	$32.6K	+3.6%	Open the original filing on SEC.gov
Sep 30, 2025	Shin Hyunsoo	Director	AGRANT	18,092	—	—	+2.6%	Open the original filing on SEC.gov
Sep 30, 2025	Lee Kyeongho	Director	AGRANT	18,092	—	—	+1.8%	Open the original filing on SEC.gov
Sep 30, 2025	Chun Kukjin	Director	AGRANT	18,092	—	—	+28.2%	Open the original filing on SEC.gov
Sep 30, 2025	Chan Nelson	Director	AGRANT	18,092	—	—	+29.9%	Open the original filing on SEC.gov
Sep 30, 2025	Barker Robert	Director	AGRANT	18,092	—	—	+23.4%	Open the original filing on SEC.gov
Sep 30, 2025	Tuder Jeffrey	Director	AGRANT	18,092	—	—	+23.6%	Open the original filing on SEC.gov
Sep 26, 2025	Schlaefer John	President, CEO & Class…	JOTHER	555	—	—	+0.3%	Open the original filing on SEC.gov
Sep 19, 2025	Kim Jeong-Min	Chief Technology Officer	AGRANT	75,000	—	—	+32.9%	Open the original filing on SEC.gov
Sep 19, 2025	Schlaefer John	President, CEO & Class…	AGRANT	75,000	—	—	+59.0%	Open the original filing on SEC.gov
Sep 19, 2025	Sum Alex	Sr. VP of Sales and…	AGRANT	75,000	—	—	+69.0%	Open the original filing on SEC.gov
Sep 19, 2025	Cheng Edmond	Chief Financial Officer	AGRANT	75,000	—	—	+98.7%	Open the original filing on SEC.gov
Sep 12, 2025	Shin Hyunsoo	Director	PBUY	44,067	$1.51	$66.5K	+6.8%	Open the original filing on SEC.gov
Sep 5, 2025	Shin Hyunsoo	Director	PBUY	10,300	$1.30	$13.4K	+1.6%	Open the original filing on SEC.gov
Sep 4, 2025	Shin Hyunsoo	Director	PBUY	8,250	$1.26	$10.4K	+1.3%	Open the original filing on SEC.gov
Aug 15, 2025	Shin Hyunsoo	Director	PBUY	121,000	$1.26	$152.5K	+23.7%	Open the original filing on SEC.gov
Jun 30, 2025	Tuder Jeffrey	Director	AGRANT	18,456	—	—	+31.6%	Open the original filing on SEC.gov
Jun 30, 2025	Shin Hyunsoo	Director	AGRANT	18,456	—	—	+3.8%	Open the original filing on SEC.gov
Jun 30, 2025	Lee Kyeongho	Director	AGRANT	18,456	—	—	+1.8%	Open the original filing on SEC.gov
Jun 30, 2025	Chun Kukjin	Director	AGRANT	18,456	—	—	+40.3%	Open the original filing on SEC.gov
Jun 30, 2025	Chan Nelson	Director	AGRANT	18,456	—	—	+43.9%	Open the original filing on SEC.gov
Jun 30, 2025	Barker Robert	Director	AGRANT	18,456	—	—	+31.4%	Open the original filing on SEC.gov
Jun 10, 2025	Shin Hyunsoo	Director	PBUY	45,000	$1.16	$52.2K	+10.1%	Open the original filing on SEC.gov
Jun 10, 2025	Shin Hyunsoo	Director	PBUY	40,000	$1.20	$48K	+9.8%	Open the original filing on SEC.gov
Jun 5, 2025	Shin Hyunsoo	Director	PBUY	21,300	$1.02	$21.7K	+5.5%	Open the original filing on SEC.gov
Jun 5, 2025	Shin Hyunsoo	Director	PBUY	58,700	$1.03	$60.5K	+17.9%	Open the original filing on SEC.gov
Jun 4, 2025	Shin Hyunsoo	Director	PBUY	80,000	$1.02	$81.6K	+32.4%	Open the original filing on SEC.gov
May 23, 2025	Shin Hyunsoo	Class II Director	PBUY	77,000	$1.04	$80.1K	+45.2%	Open the original filing on SEC.gov
May 20, 2025	Shin Hyunsoo	Class II Director	PBUY★	86,000	$1.18	$101.5K	+102.1%	Open the original filing on SEC.gov
Mar 26, 2025	Tuder Jeffrey	Director	JOTHER◆	20,734	—	—	—	Open the original filing on SEC.gov
Mar 26, 2025	Tuder Jeffrey	Director	JOTHER	16,289	—	—	+38.7%	Open the original filing on SEC.gov
Mar 26, 2024	Barker Robert	Director	AGRANT◆↺	1,867	—	—	—	Open the original filing on SEC.gov
Mar 26, 2024	Barker Robert	Director	AGRANT◆↺	933	—	—	—	Open the original filing on SEC.gov
Mar 26, 2024	Barker Robert	Director	AGRANT↺	3,735	—	—	+28.6%	Open the original filing on SEC.gov
Mar 26, 2024	Barker Robert	Director	AGRANT↺	13,074	—	—	—	Open the original filing on SEC.gov

AGRANT—

Kim Jeong-Min · Chief Technology…Sep 10

100,000 sh · +33.0% own

AGRANT—

Sum Alex · Sr. VP of Sales…Sep 10

75,000 sh · +40.8% own

AGRANT—

Schlaefer John · President, CEO &…Sep 10

150,000 sh · +74.0% own

AGRANT—

Cheng Edmond · Chief Financial…Sep 10

145,000 sh · +96.0% own

AGRANT—

Lee Kyeongho · DirectorJun 30

9,259 sh · +0.9% own

AGRANT—

Shin Hyunsoo · DirectorJun 30

9,259 sh · +1.1% own

AGRANT—

Chun Kukjin · DirectorJun 30

9,259 sh · +10.4% own

AGRANT—

Chan Nelson · DirectorJun 30

9,259 sh · +7.4% own

AGRANT—

Barker Robert · DirectorJun 30

9,259 sh · +6.5% own

AGRANT—

Tuder Jeffrey · DirectorJun 30

9,259 sh · +6.5% own

AGRANT—

Tuder Jeffrey · DirectorMar 31

24,122 sh · +20.5% own

AGRANT—

Lee Kyeongho · DirectorMar 31

24,122 sh · +2.3% own

AGRANT—

Shin Hyunsoo · DirectorMar 31

24,122 sh · +3.1% own

AGRANT—

Chun Kukjin · DirectorMar 31

24,122 sh · +37.0% own

AGRANT—

Chan Nelson · DirectorMar 31

24,122 sh · +23.8% own

AGRANT—

Barker Robert · DirectorMar 31

24,122 sh · +20.4% own

GGIFT—

Chun Kukjin · DirectorFeb 23

40,000 sh · -38.0% own

AGRANT—

Tuder Jeffrey · DirectorDec 31, 2025

22,916 sh · +24.1% own

AGRANT—

Lee Kyeongho · DirectorDec 31, 2025

22,916 sh · +2.2% own

AGRANT—

Shin Hyunsoo · DirectorDec 31, 2025

22,916 sh · +3.0% own

AGRANT—

Chun Kukjin · DirectorDec 31, 2025

22,916 sh · +27.8% own

AGRANT—

Chan Nelson · DirectorDec 31, 2025

22,916 sh · +29.1% own

AGRANT—

Barker Robert · DirectorDec 31, 2025

22,916 sh · +24.0% own

PBUY$21.4K

Shin Hyunsoo · DirectorNov 25, 2025

16,725 sh @ $1.28 · +2.3% own

PBUY$4.1K

Shin Hyunsoo · DirectorNov 21, 2025

3,180 sh @ $1.28 · +0.4% own

PBUY↓$32.6K

Shin Hyunsoo · DirectorNov 20, 2025

25,453 sh @ $1.28 · +3.6% own

AGRANT—

Shin Hyunsoo · DirectorSep 30, 2025

18,092 sh · +2.6% own

AGRANT—

Lee Kyeongho · DirectorSep 30, 2025

18,092 sh · +1.8% own

AGRANT—

Chun Kukjin · DirectorSep 30, 2025

18,092 sh · +28.2% own

AGRANT—

Chan Nelson · DirectorSep 30, 2025

18,092 sh · +29.9% own

AGRANT—

Barker Robert · DirectorSep 30, 2025

18,092 sh · +23.4% own

AGRANT—

Tuder Jeffrey · DirectorSep 30, 2025

18,092 sh · +23.6% own

JOTHER—

Schlaefer John · President, CEO &…Sep 26, 2025

555 sh · +0.3% own

AGRANT—

Kim Jeong-Min · Chief Technology…Sep 19, 2025

75,000 sh · +32.9% own

AGRANT—

Schlaefer John · President, CEO &…Sep 19, 2025

75,000 sh · +59.0% own

AGRANT—

Sum Alex · Sr. VP of Sales…Sep 19, 2025

75,000 sh · +69.0% own

AGRANT—

Cheng Edmond · Chief Financial…Sep 19, 2025

75,000 sh · +98.7% own

PBUY$66.5K

Shin Hyunsoo · DirectorSep 12, 2025

44,067 sh @ $1.51 · +6.8% own

PBUY$13.4K

Shin Hyunsoo · DirectorSep 5, 2025

10,300 sh @ $1.30 · +1.6% own

PBUY$10.4K

Shin Hyunsoo · DirectorSep 4, 2025

8,250 sh @ $1.26 · +1.3% own

PBUY$152.5K

Shin Hyunsoo · DirectorAug 15, 2025

121,000 sh @ $1.26 · +23.7% own

AGRANT—

Tuder Jeffrey · DirectorJun 30, 2025

18,456 sh · +31.6% own

AGRANT—

Shin Hyunsoo · DirectorJun 30, 2025

18,456 sh · +3.8% own

AGRANT—

Lee Kyeongho · DirectorJun 30, 2025

18,456 sh · +1.8% own

AGRANT—

Chun Kukjin · DirectorJun 30, 2025

18,456 sh · +40.3% own

AGRANT—

Chan Nelson · DirectorJun 30, 2025

18,456 sh · +43.9% own

AGRANT—

Barker Robert · DirectorJun 30, 2025

18,456 sh · +31.4% own

PBUY$52.2K

Shin Hyunsoo · DirectorJun 10, 2025

45,000 sh @ $1.16 · +10.1% own

PBUY$48K

Shin Hyunsoo · DirectorJun 10, 2025

40,000 sh @ $1.20 · +9.8% own

PBUY$21.7K

Shin Hyunsoo · DirectorJun 5, 2025

21,300 sh @ $1.02 · +5.5% own

PBUY$60.5K

Shin Hyunsoo · DirectorJun 5, 2025

58,700 sh @ $1.03 · +17.9% own

PBUY$81.6K

Shin Hyunsoo · DirectorJun 4, 2025

80,000 sh @ $1.02 · +32.4% own

PBUY$80.1K

Shin Hyunsoo · Class II DirectorMay 23, 2025

77,000 sh @ $1.04 · +45.2% own

PBUY★$101.5K

Shin Hyunsoo · Class II DirectorMay 20, 2025

86,000 sh @ $1.18 · +102.1% own

JOTHER◆—

Tuder Jeffrey · DirectorMar 26, 2025

20,734 sh

JOTHER—

Tuder Jeffrey · DirectorMar 26, 2025

16,289 sh · +38.7% own

AGRANT◆↺—

Barker Robert · DirectorMar 26, 2024

1,867 sh

AGRANT◆↺—

Barker Robert · DirectorMar 26, 2024

933 sh

AGRANT↺—

Barker Robert · DirectorMar 26, 2024

3,735 sh · +28.6% own

AGRANT↺—

Barker Robert · DirectorMar 26, 2024

13,074 sh

Filing record

How quickly insiders here report their trades. Section 16 allows two business days from the transaction.

3 of 50 filings we hold were filed after the two-business-day deadline. The furthest past the deadline was 17 business days late.

Form 4 filings made after the two-business-day deadline, with the transaction date, the filing date and the number of business days between them.
Traded	Filed	Insider	Past deadline	Largest line	Source
Mar 26, 2025	Apr 22, 2025	Tuder JeffreyDirector	17days	—	Filing ↗
Feb 23	Mar 5	Chun KukjinDirector	6days	—	Filing ↗
Jun 30	Jul 6	Tuder JeffreyDirector	1day	—	Filing ↗

Tuder JeffreyDirector

17days

Traded Mar 26, 2025 · filed Apr 22, 2025Filing ↗

Chun KukjinDirector

6days

Traded Feb 23 · filed Mar 5Filing ↗

Tuder JeffreyDirector

1day

Traded Jun 30 · filed Jul 6Filing ↗

Counted in business days from the transaction date, or the deemed execution date where the filing reports one, excluding weekends and federal holidays. How this is measured · All late filings

Insiders at this company

Everyone who has filed a Form 4 for this issuer.

More technology companies

Other issuers in the same industry with insider filings on record.

Whole sector →