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 | |
|---|---|---|---|---|---|---|
|
SNV
6476
PUT
DELISTED
Synovus
SNV
| $20K | ﹤0.01% |
400
-1,600
| -80% | -$76.9K |
|
|
GLXU
6477
T-REX 2X Long GLXY Daily Target ETF
GLXU
$11.3M
| $20K | ﹤0.01% |
+1,912
| New | +$49.6K |
|
6478
AudioCodes
AUDC
$244M
| $20K | ﹤0.01% |
2,291
-3,561
| -61% | -$32.4K |
|
6479
Expensify
EXFY
$176M
| $20K | ﹤0.01% |
+13,238
| New | +$21K |
|
6480
PUT
Carlyle Secured Lending
CGBD
$694M
| $20K | ﹤0.01% |
1,600
-2,000
| -56% | -$24.9K |
|
6481
PUT
PDF Solutions
PDFS
$1.93B
| $20K | ﹤0.01% |
+700
| New | +$19.4K |
|
6482
PUT
Kenon Holdings
KEN
$3.51B
| $19.9K | ﹤0.01% |
300
+100
| +50% | +$5.58K |
|
6483
PUT
Hyliion Holdings
HYLN
$635M
| $19.9K | ﹤0.01% |
10,800
-6,900
| -39% | -$13.9K |
|
|
ELME
6484
Elme Communities
ELME
$143M
| $19.8K | ﹤0.01% |
+1,140
| New | +$19.3K |
|
6485
Origin Bancorp
OBK
$1.69B
| $19.8K | ﹤0.01% |
527
+495
| +1,547% | +$17.7K |
|
|
SOGP
6486
CALL
Sound Group
SOGP
$50.3M
| $19.8K | ﹤0.01% |
1,700
-100
| -6% | -$1.41K |
|
|
PLYM
6487
PUT
DELISTED
Plymouth Industrial REIT
PLYM
| $19.7K | ﹤0.01% |
900
-2,000
| -69% | -$43.9K |
|
6488
CALL
WD-40
WDFC
$3.05B
| $19.7K | ﹤0.01% |
100
-1,000
| -91% | -$197K |
|
6489
Claros Mortgage Trust
CMTG
$250M
| $19.7K | ﹤0.01% |
6,428
-30
| -0.5% | -$98 |
|
|
LKFT
6490
PUT
Lakefront Biotherapeutics American Depositary Shares
LKFT
$1.78B
| $19.6K | ﹤0.01% |
600
-900
| -60% | -$29.1K |
|
|
6491
PUT
Claros Mortgage Trust
CMTG
$250M
| $19.6K | ﹤0.01% |
6,400
+3,400
| +113% | +$11.1K |
|
6492
CALL
Cerus
CERS
$433M
| $19.6K | ﹤0.01% |
9,500
-1,800
| -16% | -$3.12K |
|
|
MSTW
6493
Roundhill MSTR WeeklyPay ETF
MSTW
$33.2M
| $19.5K | ﹤0.01% |
+1,991
| New | +$37.6K |
|
6494
CALL
Sasol
SSL
$7.5B
| $19.5K | ﹤0.01% |
3,000
-11,300
| -79% | -$71.4K |
|
6495
CAE Inc. Common Shares
CAE
$8.3B
| $19.5K | ﹤0.01% |
642
-11,340
| -95% | -$318K |
|
6496
CALL
Boston Beer
SAM
$1.91B
| $19.5K | ﹤0.01% |
100
-200
| -67% | -$41.2K |
|
6497
CALL
Ocean Power Technologies
OPTT
$48.9M
| $19.4K | ﹤0.01% |
64,700
+3,600
| +6% | +$1.62K |
|
6498
CALL
Acco Brands
ACCO
$389M
| $19.4K | ﹤0.01% |
+5,200
| New | +$19.3K |
|
6499
PUT
MarineMax
HZO
$759M
| $19.4K | ﹤0.01% |
800
-1,400
| -64% | -$34.5K |
|
6500
CALL
Unitil
UTL
$970M
| $19.4K | ﹤0.01% |
+400
| New | +$19.5K |
|
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.