Vault-13

GCT SEMICONDUCTOR HLDG INC GCTS

COMMON STOCK · Common Stock · CUSIP 36170N107

55 institutional holders +21 vs Q1 2026
12,570,56212.6m shares reported held*
13.7% of all shares outstanding*
$37.3mreported value*
29 new 19 added 2 reduced 6 sold out net bought ≈ $25.4m (+8.6m shares)

* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once. Holder counts are more reliable. Shares outstanding: 92.0m as of 2026-08-06, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $2.97. Options: 4 managers hold calls ($347.8k notional), 4 hold puts ($129.5k).

Trends to Q2 2026

Institutional holders

Managers reporting a position, each quarter

0204060Q1 24: 9Q2 24: 35Q3 24: 42Q4 24: 42Q1 25: 44Q2 25: 32Q3 25: 29Q4 25: 24Q1 26: 34Q2 26: 5555Q1 24Q3 24Q1 25Q3 25Q1 26Q2 26
Numbers
QuarterHolders
Q1 20249
Q2 202435
Q3 202442
Q4 202442
Q1 202544
Q2 202532
Q3 202529
Q4 202524
Q1 202634
Q2 202655

Buyers vs sellers

Managers adding to or starting a position, vs cutting or selling out

Bought or addedCut or sold out
50050Q3 24: 21 bought or addedQ3 24: 11 cut or sold outQ4 24: 21 bought or addedQ4 24: 11 cut or sold outQ4 24Q1 25: 18 bought or addedQ1 25: 16 cut or sold outQ2 25: 21 bought or addedQ2 25: 32 cut or sold outQ2 25Q3 25: 12 bought or addedQ3 25: 22 cut or sold outQ4 25: 12 bought or addedQ4 25: 14 cut or sold outQ4 25Q1 26: 18 bought or addedQ1 26: 6 cut or sold outQ2 26: 48 bought or addedQ2 26: 8 cut or sold outQ2 26
Numbers
QuarterBought or addedCut or sold out
Q3 20242111
Q4 20242111
Q1 20251816
Q2 20252132
Q3 20251222
Q4 20251214
Q1 2026186
Q2 2026488

Calls vs puts

Options held, notional value, last 4 quarters. P/C = puts ÷ calls

CallsPuts
$0$100k$200k$300k$400kQ3 25 calls: $0Q3 25 puts: $0Q3 25P/C —Q4 25 calls: $0Q4 25 puts: $0Q4 25P/C —Q1 26 calls: $0Q1 26 puts: $0Q1 26P/C —Q2 26 calls: $347.8kQ2 26 puts: $129.5kQ2 26P/C 0.37
Numbers
QuarterCallsPutsP/C
Q3 2025$0$0—
Q4 2025$0$0—
Q1 2026$0$0—
Q2 2026$347.8k$129.5k0.37

Biggest buyers

RENAISSANCE TECHNOLOGIES LLC New +1,695,300+1.7m
MARSHALL WACE, LLP New +1,296,433+1.3m
VANGUARD CAPITAL MANAGEMENT LLC Added +1,254,181+1.3m
TUDOR INVESTMENT CORP ET AL New +818,485+818.5k
BlackRock, Inc. Added +683,217+683.2k
UBS Group AG Added +608,875+608.9k
GEODE CAPITAL MANAGEMENT, LLC Added +293,113+293.1k
Informed Momentum Co LLC New +241,246+241.2k
VANGUARD FIDUCIARY TRUST CO Added +170,673+170.7k
Robertson Stephens Wealth Management, LLC New +150,000+150.0k

Biggest sellers

Point72 Asset Management, L.P. Sold out -51,604-51.6k
HRT FINANCIAL LP Sold out -35,818-35.8k
Schonfeld Strategic Advisors LLC Sold out -13,200-13.2k
MAI Capital Management Sold out -4,400-4.4k
Arax Advisory Partners Reduced -3,040-3.0k
Tower Research Capital LLC (TRC) Sold out -2,286-2.3k
Optiver Holding B.V. Sold out -115-115
BNP PARIBAS FINANCIAL MARKETS Reduced -17-17

Biggest calls

GROUP ONE TRADING LLC New $158.3k53.3k shares
CITADEL ADVISORS LLC New $90.0k30.3k shares
SIMPLEX TRADING, LLC New $57.3k19.3k shares
JANE STREET GROUP, LLC New $42.2k14.2k shares

Biggest puts

JANE STREET GROUP, LLC New $43.7k14.7k shares
CITADEL ADVISORS LLC New $38.0k12.8k shares
SIMPLEX TRADING, LLC New $30.0k10.1k shares
GROUP ONE TRADING LLC New $17.8k6.0k shares

Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.

Major shareholders (over 5%)

Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.

HolderStakeChangeShares Last filed
SUNP Corp 13G · passive investor -3.1 pts · filed 2025-08-22 5.2% -3.1 pts 2.9m≈ $8.6m 2025-08-22

Fell to 5% or below in the last year: TD SECURITIES (USA) LLC (4.6%, 2026-05-15)

Insider purchases and sales since 1 Apr 2026

Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.

Officers and directors buying vs selling

Number of people, by quarter (10% owners not included)

BuyingSelling
101Q4 24: 0 buyingQ4 24: 0 sellingQ1 25: 0 buyingQ1 25: 0 sellingQ1 25Q2 25: 1 buyingQ2 25: 0 sellingQ3 25: 1 buyingQ3 25: 0 sellingQ3 25Q4 25: 1 buyingQ4 25: 0 sellingQ1 26: 0 buyingQ1 26: 0 sellingQ1 26Q2 26: 0 buyingQ2 26: 0 sellingQ3 26: 0 buyingQ3 26: 0 sellingQ3 26
Numbers
QuarterBuyingBoughtSellingSoldSold under a plan
Q4 20240—0——
Q1 20250—0——
Q2 20251$445.5k0——
Q3 20251$242.8k0——
Q4 20251$58.1k0——
Q1 20260—0——
Q2 20260—0——
Q3 20260—0——

None reported since 1 Apr 2026.

Holders, Q2 2026

#ManagerLocationShares Value% of their portfolioChangeShares change
1 VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio MALVERN, PA 2,999,1303.0m $8.9m $8.9m 0.00% Added +1.3m +1,254,181
2 RENAISSANCE TECHNOLOGIES LLC 0.01% of their portfolio NEW YORK, NY 1,695,3001.7m $5.0m $5.0m 0.01% New
3 MARSHALL WACE, LLP 0.00% of their portfolio LONDON, X0 1,296,4331.3m $3.9m $3.9m 0.00% New
4 BlackRock, Inc. 0.00% of their portfolio New York, NY 1,281,1641.3m $3.8m $3.8m 0.00% Added +683.2k +683,217
5 TUDOR INVESTMENT CORP ET AL 0.01% of their portfolio STAMFORD, CT 818,485818.5k $2.4m $2.4m 0.01% New
6 GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio BOSTON, MA 767,459767.5k $2.3m $2.3m 0.00% Added +293.1k +293,113
7 UBS Group AG 0.00% of their portfolio ZURICH, V8 646,238646.2k $1.9m $1.9m 0.00% Added +608.9k +608,875
8 VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio MALVERN, PA 416,917416.9k $1.2m $1.2m 0.00% Added +170.7k +170,673
9 STATE STREET CORP 0.00% of their portfolio BOSTON, MA 353,089353.1k $1.0m $1.0m 0.00% Added +112.5k +112,500
10 Informed Momentum Co LLC 0.06% of their portfolio SOLANA BEACH, CA 241,246241.2k $716.5k $716.5k 0.06% New
11 XTX Topco Ltd 0.01% of their portfolio LONDON, X0 164,717164.7k $489.2k $489.2k 0.01% Added +139.0k +139,038
12 NORTHERN TRUST CORP 0.00% of their portfolio CHICAGO, IL 155,346155.3k $461.4k $461.4k 0.00% Added +92.6k +92,645
13 Robertson Stephens Wealth Management, LLC 0.01% of their portfolio San Francisco, CA 150,000150.0k $445.5k $445.5k 0.01% New
14 SEI INVESTMENTS CO 0.00% of their portfolio OAKS, PA 142,901142.9k $424.4k $424.4k 0.00% New
15 JANE STREET GROUP, LLC 0.00% of their portfolio NEW YORK, NY 133,082133.1k $395.3k $395.3k 0.00% New
16 Team Hewins, LLC 0.10% of their portfolio FOSTER CITY, CA 125,640125.6k $373.2k $373.2k 0.10% Unchanged
17 GOLDMAN SACHS GROUP INC 0.00% of their portfolio NEW YORK, NY 112,837112.8k $335.1k $335.1k 0.00% Added +45.3k +45,324
18 ExodusPoint Capital Management, LP 0.00% of their portfolio NEW YORK, NY 88,53988.5k $263.0k $263.0k 0.00% New
19 CITADEL ADVISORS LLC 0.00% of their portfolio MIAMI, FL 77,16877.2k $229.2k $229.2k 0.00% New
20 BRIDGEWAY CAPITAL MANAGEMENT, LLC 0.00% of their portfolio HOUSTON, TX 75,00075.0k $222.8k $222.8k 0.00% Unchanged
21 Caitong International Asset Management Co., Ltd 0.03% of their portfolio HONG KONG, K3 65,81765.8k $195.5k $195.5k 0.03% Added +65.8k +65,798
22 Focus Partners Wealth 0.00% of their portfolio ST LOUIS, MO 64,00064.0k $190.1k $190.1k 0.00% New
23 BANK OF AMERICA CORP /DE/ 0.00% of their portfolio CHARLOTTE, NC 63,16463.2k $187.6k $187.6k 0.00% Added +151 +151
24 SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio BALA CYNWYD, PA 58,71358.7k $174.4k $174.4k 0.00% New
25 BRC Group Holdings, Inc. 0.04% of their portfolio LOS ANGELES, CA 56,81856.8k $168.7k $168.7k 0.04% Unchanged
26 INDEPENDENT FINANCIAL GROUP, LLC 0.00% of their portfolio SAN DIEGO, CA 49,25049.2k $146.3k $146.3k 0.00% New
27 ROYAL BANK OF CANADA 0.00% of their portfolio TORONTO, A6 49,21349.2k $146.0k $146.0k 0.00% Added +47.0k +46,956
28 MORGAN STANLEY 0.00% of their portfolio NEW YORK, NY 43,53243.5k $129.3k $129.3k 0.00% Added +24.2k +24,243
29 Jefferies Financial Group Inc. 0.00% of their portfolio NEW YORK, NY 39,40039.4k $117.0k $117.0k 0.00% New
30 Spark Investment Management LLC 0.22% of their portfolio NEW YORK, NY 37,10037.1k $110.2k $110.2k 0.22% New
31 MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio NEW YORK, NY 31,95632.0k $94.9k $94.9k 0.00% New
32 CITIGROUP INC 0.00% of their portfolio NEW YORK, NY 31,84531.8k $94.6k $94.6k 0.00% New
33 TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio NEW YORK, NY 31,73031.7k $94.2k $94.2k 0.00% New
34 Engineers Gate Manager LP 0.00% of their portfolio NEW YORK, NY 30,24830.2k $89.8k $89.8k 0.00% Added +6.7k +6,732
35 Vanguard Global Advisers, LLC 0.00% of their portfolio MALVERN, PA 27,62327.6k $82.0k $82.0k 0.00% Added +17.2k +17,242
36 AXQ CAPITAL, LP 0.01% of their portfolio JERSEY CITY, NJ 25,89825.9k $76.9k $76.9k 0.01% New
37 LPL Financial LLC 0.00% of their portfolio FORT MILL, SC 20,93520.9k $62.2k $62.2k 0.00% Added +10.9k +10,935
38 Braeburn Wealth Management LLC 0.02% of their portfolio MUSKEGON, MI 15,50015.5k $46.0k $46.0k 0.02% Unchanged
39 Rockefeller Capital Management L.P. 0.00% of their portfolio NEW YORK, NY 15,00015.0k $44.5k $44.5k 0.00% New
40 StoneX Group Inc. 0.00% of their portfolio NEW YORK, NY 12,83512.8k $37.4k $37.4k 0.00% New
41 Bank of New York Mellon Corp 0.00% of their portfolio NEW YORK, NY 12,67512.7k $37.6k $37.6k 0.00% New
42 IMC-Chicago, LLC 0.00% of their portfolio CHICAGO, IL 10,70010.7k $31.8k $31.8k 0.00% New
43 BARCLAYS PLC 0.00% of their portfolio LONDON, X0 7,0907.1k $21.1k $21.1k 0.00% New
44 SIMPLEX TRADING, LLC 0.00% of their portfolio CHICAGO, IL 7,0487.0k $20.9k $20.9k 0.00% New
45 JPMORGAN CHASE & CO 0.00% of their portfolio NEW YORK, NY 6,2136.2k $15.9k $15.9k 0.00% Added +6.0k +6,027
46 FMR LLC 0.00% of their portfolio BOSTON, MA 3,7183.7k $11.0k $11.0k 0.00% New
47 OSAIC HOLDINGS, INC. 0.00% of their portfolio SCOTTSDALE, AZ 3,4003.4k $10.1k $10.1k 0.00% Added +1.4k +1,400
48 Russell Investments Group, Ltd. 0.00% of their portfolio Seattle, WA 3,2733.3k $9.7k $9.7k 0.00% Unchanged
49 JONES FINANCIAL COMPANIES LLLP 0.00% of their portfolio DES PERES, MO 2,2002.2k $5.2k $5.2k 0.00% New
50 SBI Securities Co., Ltd. 0.00% of their portfolio TOKYO, M0 1,1151.1k $3.3k $3.3k 0.00% Added +996 +996
51 Quarry LP 0.00% of their portfolio NEW YORK, NY 1,0361.0k $3.1k $3.1k 0.00% New
52 BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio PARIS, I0 578578 $1.7k $1.7k 0.00% Reduced -17 -17
53 Avion Wealth 0.00% of their portfolio THE WOODLANDS, TX 153153 $0 $0 0.00% New
54 Arax Advisory Partners 0.00% of their portfolio NEW YORK, NY 8585 $252 $252 0.00% Reduced -3.0k -3,040
55 KERR FINANCIAL PLANNING Corp 0.00% of their portfolio FRESNO, CA 1010 $30 $30 0.00% New