Simplex Trading Portfolio holdings
Simplex Trading, founded in 2004 and headquartered in Chicago, Illinois, is a technology-driven proprietary trading firm specializing in market-making and liquidity provision, primarily in U.S. equity options and futures options. Leveraging advanced proprietary software and data-driven analysis, the firm optimizes trading strategies and develops innovative solutions to capitalize on financial market opportunities, maintaining a competitive edge through automation and a collaborative team of technologists and traders. With a workforce exceeding 300 and led by CEO Erik Swanson since 2014, Simplex operates with a low-ego, high-intelligence culture, focusing on minimal bureaucracy and rapid execution, while also making strategic venture capital investments in fintech startups. Recognized as a top workplace in Chicago by Built In’s 2025 awards, Simplex continues to evolve, blending cutting-edge technology with a commitment to market efficiency and growth.
Top Buys
| Rank | Stock | Value |
|---|---|---|
| 1 |
Netflix
NFLX
|
+$73.1M |
| 2 |
Western Digital
WDC
|
+$51.8M |
| 3 |
iShares Semiconductor ETF
SOXX
|
+$46M |
| 4 |
Meta Platforms (Facebook)
META
|
+$41.8M |
| 5 |
Alibaba
BABA
|
+$37.1M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
NVIDIA
NVDA
|
+$262M |
| 2 |
Microsoft
MSFT
|
+$194M |
| 3 |
iShares Russell 2000 ETF
IWM
|
+$149M |
| 4 |
Apple
AAPL
|
+$119M |
| 5 |
Amazon
AMZN
|
+$107M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 0.59% |
| 2 | Consumer Discretionary | 0.21% |
| 3 | Healthcare | 0.2% |
| 4 | Industrials | 0.18% |
| 5 | Communication Services | 0.16% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
|
BSOL
2901
Bitwise Solana Staking ETF
BSOL
$561M
| $756K | ﹤0.01% |
+46,116
| New | +$859K |
|
2902
PUT
Denison Mines
DNN
$2.66B
| $755K | ﹤0.01% |
284,000
+80,400
| +39% | +$219K |
|
2903
Intuitive Machines
LUNR
$2.11B
| $755K | ﹤0.01% |
46,544
-219,851
| -83% | -$2.55M |
|
2904
PUT
MannKind Corp
MNKD
$1.26B
| $754K | ﹤0.01% |
133,000
-93,000
| -41% | -$512K |
|
2905
Cellebrite
CLBT
$3.71B
| $754K | ﹤0.01% |
41,821
-8,240
| -16% | -$148K |
|
2906
Sinclair Inc
SBGI
$991M
| $754K | ﹤0.01% |
49,279
+17,099
| +53% | +$254K |
|
2907
Kodiak Gas Services
KGS
$5.83B
| $754K | ﹤0.01% |
+20,149
| New | +$712K |
|
2908
Precigen
PGEN
$1.98B
| $753K | ﹤0.01% |
180,163
-33,939
| -16% | -$131K |
|
2909
Cognyte Software
CGNT
$648M
| $753K | ﹤0.01% |
80,101
+78,443
| +4,731% | +$679K |
|
2910
Spear Alpha ETF
SPRX
$198M
| $752K | ﹤0.01% |
19,523
+14,145
| +263% | +$563K |
|
2911
CALL
Globus Medical
GMED
$10.7B
| $751K | ﹤0.01% |
8,600
-10,800
| -56% | -$820K |
|
2912
Natera
NTRA
$37.2B
| $749K | ﹤0.01% |
3,271
+1,633
| +100% | +$341K |
|
2913
PUT
Evercore
EVR
$13B
| $749K | ﹤0.01% |
2,200
+1,800
| +450% | +$579K |
|
|
HOLX
2914
DELISTED
Hologic
HOLX
| $745K | ﹤0.01% |
10,008
-10,775
| -52% | -$787K |
|
2915
CALL
The Honest Company
HNST
$424M
| $744K | ﹤0.01% |
288,400
+78,400
| +37% | +$240K |
|
2916
Pultegroup
PHM
$24.7B
| $743K | ﹤0.01% |
6,340
+5,890
| +1,309% | +$722K |
|
2917
PUT
FreightCar America
RAIL
$277M
| $743K | ﹤0.01% |
67,100
+60,400
| +901% | +$555K |
|
2918
PUT
Herc Holdings
HRI
$5.31B
| $742K | ﹤0.01% |
5,000
+2,100
| +72% | +$288K |
|
2919
Trade Desk
TTD
$8.6B
| $742K | ﹤0.01% |
+19,538
| New | +$866K |
|
|
PENG
2920
CALL
Penguin Solutions Inc
PENG
$2.67B
| $741K | ﹤0.01% |
37,900
-21,400
| -36% | -$459K |
|
2921
EOG Resources
EOG
$75.6B
| $740K | ﹤0.01% |
+7,049
| New | +$757K |
|
2922
Colgate-Palmolive
CL
$73.3B
| $740K | ﹤0.01% |
9,361
-20,037
| -68% | -$1.57M |
|
|
HTGCR
2923
CALL
DELISTED
HERCULES TECHNOLOGY GROWTH CAP INC TRANS RGTS TO PUR COM STK
HTGCR
| $738K | ﹤0.01% |
39,200
+26,600
| +211% | +$501K |
|
2924
CALL
Humacyte
HUMA
$182M
| $737K | ﹤0.01% |
766,900
+621,200
| +426% | +$880K |
|
|
NXRT
2925
NexPoint Residential Trust
NXRT
$674M
| $735K | ﹤0.01% |
24,424
+24,408
| +152,550% | +$748K |
|
Similar funds
Simplex Trading's Q4 2025 Portfolio in Review
As of Q4 2025, Simplex Trading held 10,526 positions worth $177B, down 9% from $195B the previous quarter. Its ten largest holdings account for 49% of the portfolio.
Simplex Trading withdrew a net $23.2B in Q4 2025, closing 2,184 positions and reducing 4,088 holdings. Its most notable exit was iShares Russell 2000 ETF, an estimated $149M position sold in full.
By sector, the portfolio is most concentrated in Technology at 0.59% of assets, down from 0.79% a quarter earlier, followed by Consumer Discretionary and Healthcare.
Against the trend, Simplex Trading opened a new position in Western Digital worth $58.9M.
- Simplex Trading's largest Q4 2025 buy was Western Digital: 341,762 shares worth $58.9M.
- Simplex Trading added most to Netflix in Q4 2025, an estimated $73.1M increase.
- Simplex Trading's biggest Q4 2025 reduction was NVIDIA, cutting an estimated $262M.
- Simplex Trading fully exited iShares Russell 2000 ETF in Q4 2025, selling an estimated $149M.
- Simplex Trading's ten largest holdings make up 49% of its $177B portfolio in Q4 2025.
- Simplex Trading opened 1,476 new positions and closed 2,184 in Q4 2025.
- Simplex Trading's portfolio value fell 9% quarter-over-quarter to $177B.
Based on Simplex Trading's 13F filing for Q4 2025, filed 11 Feb 2026.