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 | |
|---|---|---|---|---|---|---|
4201
WD-40
WDFC
$2.98B
| $208K | ﹤0.01% |
+1,056
| New | +$208K |
|
4202
PUT
Goldman Sachs BDC
GSBD
$997M
| $208K | ﹤0.01% |
+22,400
| New | +$220K |
|
4203
CALL
US Gold Corp
USAU
$213M
| $208K | ﹤0.01% |
10,700
-25,900
| -71% | -$443K |
|
4204
PUT
Public Storage
PSA
$61.5B
| $208K | ﹤0.01% |
800
-4,500
| -85% | -$1.26M |
|
4205
Village Farms International
VFF
$240M
| $208K | ﹤0.01% |
56,859
-94,316
| -62% | -$328K |
|
4206
CALL
IDEAYA Biosciences
IDYA
$3.43B
| $207K | ﹤0.01% |
6,000
+4,700
| +362% | +$150K |
|
4207
PUT
Brown & Brown
BRO
$25.1B
| $207K | ﹤0.01% |
2,600
+200
| +8% | +$16.7K |
|
|
BNC
4208
CEA Industries
BNC
$103M
| $207K | ﹤0.01% |
32,271
+19,376
| +150% | +$136K |
|
4209
CALL
Sundial Growers
SNDL
$312M
| $207K | ﹤0.01% |
124,700
+8,900
| +8% | +$17.9K |
|
4210
CALL
eHealth
EHTH
$41.9M
| $207K | ﹤0.01% |
+45,000
| New | +$198K |
|
4211
RxSight
RXST
$254M
| $206K | ﹤0.01% |
19,798
-3,556
| -15% | -$35.7K |
|
4212
CALL
Construction Partners
ROAD
$5.88B
| $206K | ﹤0.01% |
1,900
+800
| +73% | +$90.1K |
|
|
SOBO
4213
CALL
South Bow Corp
SOBO
$7.79B
| $206K | ﹤0.01% |
7,500
+4,400
| +142% | +$120K |
|
4214
Aldeyra Therapeutics
ALDX
$97.1M
| $206K | ﹤0.01% |
39,755
+10,579
| +36% | +$54.3K |
|
4215
CALL
UGI
UGI
$7.87B
| $206K | ﹤0.01% |
5,500
-19,100
| -78% | -$676K |
|
4216
PUT
Newell Brands
NWL
$2.21B
| $205K | ﹤0.01% |
55,000
+18,000
| +49% | +$72.7K |
|
4217
CALL
Immersion
IMMR
$243M
| $204K | ﹤0.01% |
30,000
+1,700
| +6% | +$11.5K |
|
4218
PUT
Microbot Medical
MBOT
$112M
| $204K | ﹤0.01% |
102,000
-9,100
| -8% | -$21.6K |
|
4219
Teekay
TK
$996M
| $204K | ﹤0.01% |
22,591
-18,876
| -46% | -$174K |
|
4220
iShares Latin America 40 ETF
ILF
$3.73B
| $204K | ﹤0.01% |
6,699
+2,118
| +46% | +$63.1K |
|
|
QVCGA
4221
PUT
DELISTED
QVC Group Inc Series A
QVCGA
| $204K | ﹤0.01% |
19,500
-9,200
| -32% | -$100K |
|
4222
PUT
Teucrium Corn Fund
CORN
$178M
| $204K | ﹤0.01% |
+10,400
| New | +$185K |
|
4223
CALL
GATX Corp
GATX
$6.45B
| $204K | ﹤0.01% |
1,200
| – | – |
|
4224
PUT
Keysight
KEYS
$50.7B
| $203K | ﹤0.01% |
1,000
-17,500
| -95% | -$3.25M |
|
4225
CALL
Pilgrim's Pride
PPC
$7.13B
| $203K | ﹤0.01% |
5,200
-300
| -5% | -$11.5K |
|
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.