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 | |
|---|---|---|---|---|---|---|
5476
CALL
NewtekOne
NEWT
$428M
| $61.3K | ﹤0.01% |
5,400
-3,800
| -41% | -$41.4K |
|
|
ACRE
5477
CALL
Ares Commercial Real Estate
ACRE
$236M
| $61.2K | ﹤0.01% |
12,800
+3,700
| +41% | +$18K |
|
5478
OceanFirst Financial
OCFC
$1.68B
| $61.2K | ﹤0.01% |
+3,408
| New | +$63.7K |
|
5479
PUT
COPT Defense Properties
CDP
$4.3B
| $61.2K | ﹤0.01% |
2,200
| – | – |
|
5480
PUT
Blue Bird Corp
BLBD
$2.35B
| $61.1K | ﹤0.01% |
1,300
-7,700
| -86% | -$403K |
|
5481
CALL
StealthGas
GASS
$332M
| $61.1K | ﹤0.01% |
8,700
+3,600
| +71% | +$24.2K |
|
|
RAPT
5482
CALL
DELISTED
RAPT Therapeutics
RAPT
| $61K | ﹤0.01% |
1,800
-13,900
| -89% | -$432K |
|
5483
CALL
Phreesia
PHR
$663M
| $60.9K | ﹤0.01% |
3,600
+1,200
| +50% | +$24.8K |
|
5484
Inseego
INSG
$114M
| $60.9K | ﹤0.01% |
5,928
-5,854
| -50% | -$76K |
|
5485
CALL
Woodside Energy
WDS
$44.6B
| $60.8K | ﹤0.01% |
3,900
-16,600
| -81% | -$264K |
|
5486
PUT
GeoPark
GPRK
$633M
| $60.8K | ﹤0.01% |
8,200
-8,600
| -51% | -$63K |
|
5487
Westwater Resources
WWR
$52.4M
| $60.7K | ﹤0.01% |
+80,919
| New | +$100K |
|
5488
CALL
Equity Lifestyle Properties
ELS
$12.6B
| $60.6K | ﹤0.01% |
1,000
-100
| -9% | -$6.18K |
|
5489
CALL
Columbia Sportswear
COLM
$3.04B
| $60.6K | ﹤0.01% |
1,100
+700
| +175% | +$37.4K |
|
5490
PUT
Taysha Gene Therapies
TSHA
$1.68B
| $60.5K | ﹤0.01% |
+11,000
| New | +$53.4K |
|
|
LOVE
5491
PUT
DELISTED
LoveSac
LOVE
| $60.5K | ﹤0.01% |
4,100
-600
| -13% | -$8.48K |
|
5492
PUT
Butterfly Network
BFLY
$1.89B
| $60.4K | ﹤0.01% |
15,900
-4,200
| -21% | -$11.4K |
|
5493
PUT
Adeia
ADEA
$2.94B
| $60.4K | ﹤0.01% |
+3,500
| New | +$51.9K |
|
5494
Organogenesis Holdings
ORGO
$305M
| $60.2K | ﹤0.01% |
+11,616
| New | +$56.3K |
|
5495
CALL
Fulton Financial
FULT
$4.66B
| $59.9K | ﹤0.01% |
3,100
+2,000
| +182% | +$36.8K |
|
5496
CALL
Gain Therapeutics
GANX
$71.7M
| $59.9K | ﹤0.01% |
18,600
-64,100
| -78% | -$171K |
|
|
OTLY
5497
CALL
Oatly Group
OTLY
$465M
| $59.9K | ﹤0.01% |
62,800
+3,800
| +6% | +$50.3K |
|
5498
CALL
LG Display
LPL
$3B
| $59.8K | ﹤0.01% |
14,200
-4,300
| -23% | -$20.1K |
|
|
MEME
5499
Roundhill Meme Stock ETF
MEME
$13.2M
| $59.8K | ﹤0.01% |
+9,640
| New | +$73K |
|
5500
Everspin Technologies
MRAM
$341M
| $59.7K | ﹤0.01% |
6,438
+1,406
| +28% | +$13.4K |
|
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.