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 | |
|---|---|---|---|---|---|---|
7401
Equity Bancshares
EQBK
$1.04B
| $5.27K | ﹤0.01% |
118
-1
| -0.8% | -$43 |
|
7402
PUT
Tyra Biosciences
TYRA
$1.85B
| $5.26K | ﹤0.01% |
200
+100
| +100% | +$1.84K |
|
7403
CALL
VEON
VEON
$3.5B
| $5.26K | ﹤0.01% |
100
-1,100
| -92% | -$55.7K |
|
7404
CALL
Immatics
IMTX
$1.23B
| $5.25K | ﹤0.01% |
500
-12,800
| -96% | -$129K |
|
7405
PUT
UNIFI
UFI
$114M
| $5.25K | ﹤0.01% |
1,500
-2,100
| -58% | -$8.12K |
|
7406
CALL
Independence Realty Trust
IRT
$3.98B
| $5.24K | ﹤0.01% |
300
-1,000
| -77% | -$16.6K |
|
7407
CALL
Caledonia Mining Corp
CMCL
$351M
| $5.23K | ﹤0.01% |
200
-900
| -82% | -$26.5K |
|
|
JFIN
7408
PUT
Jiayin Group
JFIN
$115M
| $5.22K | ﹤0.01% |
900
-8,400
| -90% | -$70.8K |
|
7409
PUT
Offerpad Solutions
OPAD
$18.5M
| $5.2K | ﹤0.01% |
430
-7,530
| -95% | -$167K |
|
7410
CALL
Newmark Group
NMRK
$2.64B
| $5.2K | ﹤0.01% |
+300
| New | +$5.26K |
|
7411
PUT
Pacira BioSciences
PCRX
$1.04B
| $5.18K | ﹤0.01% |
200
-300
| -60% | -$7.13K |
|
7412
VanEck Preferred Securities ex Financials ETF
PFXF
$2.37B
| $5.17K | ﹤0.01% |
+293
| New | +$5.19K |
|
7413
CALL
Unity Bancorp
UNTY
$590M
| $5.17K | ﹤0.01% |
100
| – | – |
|
7414
CALL
Metallus
MTUS
$833M
| $5.15K | ﹤0.01% |
300
-6,300
| -95% | -$108K |
|
7415
Fuel Tech
FTEK
$43M
| $5.15K | ﹤0.01% |
3,299
-39,202
| -92% | -$86.3K |
|
7416
Adeia
ADEA
$2.55B
| $5.14K | ﹤0.01% |
+298
| New | +$4.42K |
|
|
ANGX
7417
CALL
Angel Studios
ANGX
$731M
| $5.14K | ﹤0.01% |
+1,100
| New | +$6.52K |
|
7418
iShares MSCI Indonesia ETF
EIDO
$466M
| $5.12K | ﹤0.01% |
274
-525
| -66% | -$9.6K |
|
7419
PUT
CytomX Therapeutics
CTMX
$690M
| $5.11K | ﹤0.01% |
1,200
-11,000
| -90% | -$41.8K |
|
7420
Celularity
CELU
$19.4M
| $5.11K | ﹤0.01% |
4,603
-4,848
| -51% | -$8.69K |
|
7421
CALL
Compañía de Cervecerías Unidas
CCU
$2.14B
| $5.1K | ﹤0.01% |
400
-300
| -43% | -$3.79K |
|
7422
Dominari Holdings
DOMH
$50.4M
| $5.1K | ﹤0.01% |
+1,030
| New | +$5.26K |
|
7423
PUT
Healthcare Realty
HR
$7.56B
| $5.08K | ﹤0.01% |
300
-67,800
| -100% | -$1.21M |
|
7424
CALL
Latham Group
SWIM
$660M
| $5.08K | ﹤0.01% |
800
| – | – |
|
7425
Cineverse
CNVS
$56.9M
| $5.07K | ﹤0.01% |
+2,404
| New | +$6.51K |
|
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.