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 | |
|---|---|---|---|---|---|---|
7276
Webster Financial
WBS
$12.3B
| $6.54K | ﹤0.01% |
+104
| New | +$6.17K |
|
|
ACLX
7277
CALL
DELISTED
Arcellx
ACLX
| $6.52K | ﹤0.01% |
100
-4,600
| -98% | -$367K |
|
7278
Tilly's
TLYS
$114M
| $6.52K | ﹤0.01% |
3,276
-9,490
| -74% | -$15.5K |
|
|
KYIV
7279
PUT
Kyivstar Group
KYIV
$3.03B
| $6.49K | ﹤0.01% |
500
-60,100
| -99% | -$792K |
|
|
AIS
7280
VistaShares Artificial Intelligence Supercycle ETF
AIS
$730M
| $6.46K | ﹤0.01% |
+171
| New | +$6.42K |
|
7281
PUT
The Honest Company
HNST
$412M
| $6.45K | ﹤0.01% |
2,500
-22,800
| -90% | -$69.9K |
|
|
AIRO
7282
AIRO Group Holdings
AIRO
$196M
| $6.45K | ﹤0.01% |
788
-4,517
| -85% | -$58.2K |
|
7283
PUT
ASE Group
ASX
$68.3B
| $6.44K | ﹤0.01% |
400
+200
| +100% | +$2.84K |
|
7284
The Oncology Institute
TOI
$477M
| $6.43K | ﹤0.01% |
+1,806
| New | +$6.7K |
|
7285
CALL
Graham Corp
GHM
$1.03B
| $6.42K | ﹤0.01% |
100
-800
| -89% | -$48.3K |
|
7286
CALL
SITE Centers
SITC
$236M
| $6.42K | ﹤0.01% |
1,000
| – | – |
|
7287
RPC Inc
RES
$1.13B
| $6.42K | ﹤0.01% |
+1,180
| New | +$6.13K |
|
7288
Monarch Casino & Resort
MCRI
$2.2B
| $6.41K | ﹤0.01% |
+67
| New | +$6.44K |
|
|
GOOD
7289
CALL
Gladstone Commercial Corp
GOOD
$623M
| $6.4K | ﹤0.01% |
600
-300
| -33% | -$3.33K |
|
7290
PUT
RLI Corp
RLI
$6.02B
| $6.4K | ﹤0.01% |
+100
| New | +$6.28K |
|
7291
CALL
E.W. Scripps
SSP
$270M
| $6.38K | ﹤0.01% |
+1,600
| New | +$5.38K |
|
|
AIBU
7292
Direxion Daily AI and Big Data Bull 2X ETF
AIBU
$20.3M
| $6.37K | ﹤0.01% |
+129
| New | +$7.1K |
|
7293
CALL
Unicycive Therapeutics
UNCY
$130M
| $6.35K | ﹤0.01% |
+1,100
| New | +$5.87K |
|
7294
CALL
Atkore
ATKR
$2.41B
| $6.33K | ﹤0.01% |
100
-4,700
| -98% | -$307K |
|
7295
VOC Energy
VOC
$56.4M
| $6.3K | ﹤0.01% |
2,333
-2,839
| -55% | -$8.3K |
|
7296
PUT
Cohen & Steers
CNS
$4.2B
| $6.28K | ﹤0.01% |
100
| – | – |
|
7297
CALL
First Internet Bancorp
INBK
$233M
| $6.26K | ﹤0.01% |
+300
| New | +$6.03K |
|
7298
iShares Core Dividend Growth ETF
DGRO
$42.8B
| $6.25K | ﹤0.01% |
+90
| New | +$6.19K |
|
7299
Enlivex Ltd
ENLV
$37.9M
| $6.24K | ﹤0.01% |
+592
| New | +$8.83K |
|
7300
CALL
Chefs' Warehouse
CHEF
$4.31B
| $6.23K | ﹤0.01% |
100
-2,100
| -95% | -$126K |
|
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.