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 | |
|---|---|---|---|---|---|---|
7226
Innoviva
INVA
$1.6B
| $6.96K | ﹤0.01% |
348
+24
| +7% | +$469 |
|
|
TOFR
7227
PUT
DELISTED
Stock Split Index Fund
TOFR
| $6.95K | ﹤0.01% |
+200
| New | +$6.95K |
|
7228
PUT
Immunocore
IMCR
$1.7B
| $6.94K | ﹤0.01% |
+200
| New | +$7.06K |
|
|
AMRN
7229
Amarin Corp
AMRN
$297M
| $6.89K | ﹤0.01% |
+494
| New | +$8.15K |
|
7230
Goldgroup Mining Inc.
GORO
$155M
| $6.88K | ﹤0.01% |
8,308
-3,892
| -32% | -$3.1K |
|
7231
VanEck Bitcoin Trust
HODL
$1.06B
| $6.87K | ﹤0.01% |
+278
| New | +$7.87K |
|
7232
PUT
Orion
OEC
$403M
| $6.86K | ﹤0.01% |
+1,300
| New | +$7.05K |
|
7233
PUT
Ingles Markets
IMKTA
$1.72B
| $6.86K | ﹤0.01% |
100
| – | – |
|
7234
CALL
DocGo
DCGO
$64.2M
| $6.85K | ﹤0.01% |
7,800
-4,300
| -36% | -$4.59K |
|
7235
iShares US Infrastructure ETF
IFRA
$4.45B
| $6.84K | ﹤0.01% |
+130
| New | +$6.87K |
|
7236
Lantern Pharma
LTRN
$32M
| $6.84K | ﹤0.01% |
2,257
+831
| +58% | +$3.09K |
|
7237
First Trust Health Care AlphaDEX Fund
FXH
$1.05B
| $6.83K | ﹤0.01% |
+60
| New | +$6.8K |
|
7238
Tyler Technologies
TYL
$13.7B
| $6.81K | ﹤0.01% |
15
-1,125
| -99% | -$536K |
|
7239
PUT
MicroSectors FANG+ ETNs due Jan 8 2038
FNGS
$532M
| $6.8K | ﹤0.01% |
100
-300
| -75% | -$21.1K |
|
7240
PUT
Assembly Biosciences
ASMB
$498M
| $6.8K | ﹤0.01% |
+200
| New | +$6.44K |
|
|
ALH
7241
PUT
Alliance Laundry Holdings
ALH
$5.16B
| $6.79K | ﹤0.01% |
+2,300
| New | +$55.3K |
|
7242
PUT
Northeast Community Bancorp
NECB
$373M
| $6.78K | ﹤0.01% |
300
| – | – |
|
7243
TechTarget
TTGT
$327M
| $6.78K | ﹤0.01% |
1,256
+203
| +19% | +$1.09K |
|
7244
Vanguard Short-Term Bond ETF
BSV
$44.7B
| $6.78K | ﹤0.01% |
86
-971
| -92% | -$76.6K |
|
7245
Atea Pharmaceuticals
AVIR
$370M
| $6.76K | ﹤0.01% |
1,895
-44,325
| -96% | -$141K |
|
7246
CALL
Vivani Medical
VANI
$109M
| $6.76K | ﹤0.01% |
5,500
+1,500
| +38% | +$2.17K |
|
7247
Oneok
OKE
$56.7B
| $6.76K | ﹤0.01% |
+92
| New | +$6.52K |
|
7248
PUT
The Bancorp
TBBK
$2.81B
| $6.75K | ﹤0.01% |
+100
| New | +$6.9K |
|
7249
CALL
Anika Therapeutics
ANIK
$215M
| $6.73K | ﹤0.01% |
+700
| New | +$6.7K |
|
7250
Carriage Services
CSV
$647M
| $6.72K | ﹤0.01% |
159
-707
| -82% | -$30.7K |
|
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.