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 | |
|---|---|---|---|---|---|---|
|
DRD
5176
PUT
DRDGold
DRD
$1.77B
| $83.7K | ﹤0.01% |
2,700
-14,400
| -84% | -$411K |
|
5177
WPP
WPP
$4.36B
| $83.4K | ﹤0.01% |
3,715
+3,484
| +1,508% | +$74.9K |
|
5178
CALL
Xometry
XMTR
$4.74B
| $83.3K | ﹤0.01% |
1,400
-10,100
| -88% | -$569K |
|
5179
CALL
Flowserve
FLS
$9.71B
| $83.3K | ﹤0.01% |
1,200
-10,000
| -89% | -$643K |
|
5180
PUT
Krispy Kreme
DNUT
$548M
| $83.2K | ﹤0.01% |
20,700
-23,300
| -53% | -$92.2K |
|
5181
Spero Therapeutics
SPRO
$67.7M
| $83.1K | ﹤0.01% |
35,686
+28,068
| +368% | +$65.2K |
|
|
MOMO
5182
Hello Group
MOMO
$885M
| $83.1K | ﹤0.01% |
12,686
-12,132
| -49% | -$83.5K |
|
5183
CALL
CGI
GIB
$15.1B
| $83.1K | ﹤0.01% |
900
+700
| +350% | +$62.4K |
|
5184
CALL
Ovid Therapeutics
OVID
$414M
| $83K | ﹤0.01% |
50,900
+47,100
| +1,239% | +$72.5K |
|
|
SEE
5185
PUT
DELISTED
Sealed Air
SEE
| $82.9K | ﹤0.01% |
2,000
+600
| +43% | +$23.2K |
|
|
CMRC
5186
CALL
Commerce.com Inc Series 1
CMRC
$258M
| $82.8K | ﹤0.01% |
20,100
+5,600
| +39% | +$25.8K |
|
5187
Upbound Group
UPBD
$1.13B
| $82.8K | ﹤0.01% |
4,715
+603
| +15% | +$11.7K |
|
|
SHOE
5188
PUT
Shoe Station Group
SHOE
$413M
| $82.7K | ﹤0.01% |
4,900
+3,600
| +277% | +$66.1K |
|
|
OSG
5189
Octave Specialty Group
OSG
$243M
| $82.6K | ﹤0.01% |
10,611
-10,267
| -49% | -$87.7K |
|
|
BTCL
5190
T-Rex 2X Long Bitcoin Daily Target ETF
BTCL
$21.8M
| $82.4K | ﹤0.01% |
2,849
+822
| +41% | +$34.3K |
|
|
COLO
5191
Global X MSCI Colombia ETF
COLO
$206M
| $82.1K | ﹤0.01% |
2,304
+1,811
| +367% | +$64.8K |
|
5192
CALL
Smart Sand
SND
$185M
| $82K | ﹤0.01% |
20,500
+11,100
| +118% | +$31.4K |
|
5193
CALL
Neonode
NEON
$14.1M
| $81.8K | ﹤0.01% |
47,000
-39,100
| -45% | -$103K |
|
5194
US Global GO Gold and Precious Metal Miners ETF
GOAU
$161M
| $81.7K | ﹤0.01% |
1,920
+894
| +87% | +$36K |
|
5195
CALL
KT
KT
$8.62B
| $81.6K | ﹤0.01% |
4,300
+1,400
| +48% | +$26.1K |
|
5196
CALL
Encore Capital Group
ECPG
$2.02B
| $81.5K | ﹤0.01% |
1,500
-1,000
| -40% | -$48.2K |
|
5197
Interparfums
IPAR
$3.99B
| $81.5K | ﹤0.01% |
961
+151
| +19% | +$13.3K |
|
5198
NovoCure
NVCR
$1.73B
| $81.5K | ﹤0.01% |
6,301
-1,514
| -19% | -$19.4K |
|
5199
Asure Software
ASUR
$232M
| $81.2K | ﹤0.01% |
8,618
+5,938
| +222% | +$49.9K |
|
5200
PUT
Vera Therapeutics
VERA
$2.3B
| $81K | ﹤0.01% |
1,600
-1,500
| -48% | -$53.3K |
|
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.