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 | |
|---|---|---|---|---|---|---|
7976
Fidelity MSCI Real Estate Index ETF
FREL
$1.54B
| $1.24K | ﹤0.01% |
+46
| New | +$1.25K |
|
7977
CALL
Algonquin Power & Utilities
AQN
$4.71B
| $1.23K | ﹤0.01% |
200
-6,100
| -97% | -$36.2K |
|
7978
PUT
Ardagh Metal Packaging
AMBP
$3.05B
| $1.23K | ﹤0.01% |
300
-23,400
| -99% | -$88.8K |
|
7979
Natural Health Trends
NHTC
$15.8M
| $1.23K | ﹤0.01% |
397
-238
| -37% | -$863 |
|
7980
Usio Inc
USIO
$53.5M
| $1.23K | ﹤0.01% |
901
+795
| +750% | +$1.13K |
|
7981
CALL
CI&T Inc
CINT
$420M
| $1.22K | ﹤0.01% |
+300
| New | +$1.36K |
|
|
SKYA
7982
PUT
SkyAI Inc
SKYA
$59.7M
| $1.22K | ﹤0.01% |
+600
| New | +$2.31K |
|
7983
CALL
IGC Pharma
IGC
$26.9M
| $1.21K | ﹤0.01% |
+4,300
| New | +$1.53K |
|
7984
CALL
Noodles & Co
NDLS
$88.5M
| $1.2K | ﹤0.01% |
+213
| New | +$1.21K |
|
7985
PUT
Century Casinos
CNTY
$33.2M
| $1.2K | ﹤0.01% |
+900
| New | +$1.61K |
|
7986
CALL
XBiotech
XBIT
$69.2M
| $1.2K | ﹤0.01% |
+500
| New | +$1.23K |
|
7987
PUT
Puma Biotechnology
PBYI
$402M
| $1.19K | ﹤0.01% |
+200
| New | +$1.06K |
|
7988
PUT
Wrap Technologies
WRAP
$95.3M
| $1.19K | ﹤0.01% |
500
-10,100
| -95% | -$24.4K |
|
7989
1st Source
SRCE
$2.18B
| $1.19K | ﹤0.01% |
19
-80
| -81% | -$4.95K |
|
|
TOUR
7990
Tuniu
TOUR
$56.9M
| $1.19K | ﹤0.01% |
192
+170
| +773% | +$1.34K |
|
7991
CALL
8x8 Inc
EGHT
$269M
| $1.18K | ﹤0.01% |
600
-6,300
| -91% | -$12.4K |
|
7992
iShares MSCI Brazil Small-Cap ETF
EWZS
$232M
| $1.18K | ﹤0.01% |
91
-374
| -80% | -$5.04K |
|
7993
PUT
Televisa
TV
$1.47B
| $1.16K | ﹤0.01% |
+400
| New | +$1.09K |
|
7994
Prairie Operating Co
PROP
$67.9M
| $1.16K | ﹤0.01% |
687
-5,598
| -89% | -$10.2K |
|
7995
PUT
Telecom Argentina
TEO
$5.85B
| $1.16K | ﹤0.01% |
100
-200
| -67% | -$2.15K |
|
7996
PUT
Leslie's
LESL
$10M
| $1.16K | ﹤0.01% |
700
+100
| +17% | +$324 |
|
|
CMBM
7997
PUT
DELISTED
Cambium Networks
CMBM
| $1.15K | ﹤0.01% |
+800
| New | +$1.36K |
|
7998
Lyell Immunopharma
LYEL
$318M
| $1.14K | ﹤0.01% |
37
-125
| -77% | -$2.8K |
|
7999
Pacer BlueStar Digital Entertainment ETF
ODDS
$3.99M
| $1.14K | ﹤0.01% |
+39
| New | +$1.19K |
|
|
TSLW
8000
Roundhill TSLA WeeklyPay ETF
TSLW
$109M
| $1.13K | ﹤0.01% |
+34
| New | +$1.23K |
|
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.