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 | |
|---|---|---|---|---|---|---|
5851
Orion Group Holdings
ORN
$396M
| $40.5K | ﹤0.01% |
4,070
+1,901
| +88% | +$18.4K |
|
5852
Penumbra
PEN
$12.7B
| $40.4K | ﹤0.01% |
+130
| New | +$35.9K |
|
5853
Ampco-Pittsburgh
AP
$163M
| $40.4K | ﹤0.01% |
7,573
+3,725
| +97% | +$10.3K |
|
5854
PUT
Valmont Industries
VMI
$9.3B
| $40.2K | ﹤0.01% |
+100
| New | +$40.7K |
|
5855
CALL
Gerdau
GGB
$9.74B
| $40.2K | ﹤0.01% |
+10,900
| New | +$38.1K |
|
5856
CALL
Kforce
KFRC
$1.02B
| $40.2K | ﹤0.01% |
1,300
+400
| +44% | +$11.8K |
|
5857
PUT
Impact Shares Womens Empowerment ETF Trading
WOMN
$57.3M
| $40.2K | ﹤0.01% |
2,000
+1,900
| +1,900% | +$77.7K |
|
5858
CALL
CRA International
CRAI
$1.16B
| $40.1K | ﹤0.01% |
200
-200
| -50% | -$37.7K |
|
5859
CALL
Funko
FNKO
$326M
| $40.1K | ﹤0.01% |
11,800
+2,600
| +28% | +$8.18K |
|
5860
PUT
Haemonetics
HAE
$3.89B
| $40.1K | ﹤0.01% |
500
-3,000
| -86% | -$202K |
|
|
MCW
5861
CALL
DELISTED
Mister Car Wash
MCW
| $40K | ﹤0.01% |
+7,200
| New | +$37.9K |
|
5862
PUT
Lyell Immunopharma
LYEL
$317M
| $40K | ﹤0.01% |
1,300
| – | – |
|
5863
PUT
Quanex
NX
$819M
| $40K | ﹤0.01% |
2,600
+2,500
| +2,500% | +$35.3K |
|
|
SUIG
5864
Sui Group Holdings
SUIG
$69.6M
| $39.9K | ﹤0.01% |
23,895
-25,859
| -52% | -$66.8K |
|
5865
US Physical Therapy
USPH
$1.2B
| $39.9K | ﹤0.01% |
+511
| New | +$41.5K |
|
|
FFWM
5866
DELISTED
First Foundation Inc
FFWM
| $39.7K | ﹤0.01% |
+6,446
| New | +$36.1K |
|
|
RKLX
5867
Defiance Daily Target 2X Long RKLB ETF
RKLX
$162M
| $39.7K | ﹤0.01% |
+997
| New | +$36.6K |
|
5868
PUT
Kinetik
KNTK
$3.72B
| $39.7K | ﹤0.01% |
1,100
+700
| +175% | +$25.3K |
|
|
SILA
5869
PUT
DELISTED
Sila Realty Trust
SILA
| $39.6K | ﹤0.01% |
1,700
+500
| +42% | +$11.8K |
|
5870
Nomura Holdings
NMR
$28.3B
| $39.5K | ﹤0.01% |
4,714
+3,291
| +231% | +$24.6K |
|
5871
Park Hotels & Resorts
PK
$3.03B
| $39.5K | ﹤0.01% |
+3,776
| New | +$40.4K |
|
5872
CALL
Rackspace Technology
RXT
$1.05B
| $39.4K | ﹤0.01% |
40,600
+31,000
| +323% | +$39K |
|
5873
Vanguard FTSE Developed Markets ETF
VEA
$229B
| $39.4K | ﹤0.01% |
+630
| New | +$38.6K |
|
5874
Ceco Environmental
CECO
$3.85B
| $39.3K | ﹤0.01% |
+657
| New | +$35.1K |
|
5875
Direxion Daily Healthcare Bull 3X ETF
CURE
$172M
| $39.3K | ﹤0.01% |
352
-759
| -68% | -$77.6K |
|
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.