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 | |
|---|---|---|---|---|---|---|
6326
PUT
Tenable Holdings
TENB
$3.6B
| $23.5K | ﹤0.01% |
1,000
+700
| +233% | +$19.1K |
|
6327
America Movil
AMX
$76.1B
| $23.5K | ﹤0.01% |
1,138
-9,482
| -89% | -$209K |
|
6328
CALL
Blue Bird Corp
BLBD
$2.35B
| $23.5K | ﹤0.01% |
500
-1,600
| -76% | -$83.7K |
|
6329
CALL
Ooma
OOMA
$598M
| $23.5K | ﹤0.01% |
2,000
+1,000
| +100% | +$11.4K |
|
6330
PUT
Clean Harbors
CLH
$16.5B
| $23.4K | ﹤0.01% |
100
-2,500
| -96% | -$571K |
|
6331
PUT
Palladyne AI
PDYN
$247M
| $23.4K | ﹤0.01% |
5,500
-99,500
| -95% | -$670K |
|
6332
PUT
Service Corp International
SCI
$11.7B
| $23.4K | ﹤0.01% |
300
-13,300
| -98% | -$1.06M |
|
6333
CALL
Tanger
SKT
$4.67B
| $23.4K | ﹤0.01% |
700
-2,200
| -76% | -$73.3K |
|
6334
CALL
Brink's
BCO
$4.88B
| $23.3K | ﹤0.01% |
200
-800
| -80% | -$91.5K |
|
6335
CALL
Castle Biosciences
CSTL
$855M
| $23.3K | ﹤0.01% |
+600
| New | +$19.3K |
|
|
MTA
6336
PUT
Metalla Royalty & Streaming
MTA
$688M
| $23.3K | ﹤0.01% |
+3,000
| New | +$21.6K |
|
|
XRPC
6337
CALL
Canary XRP ETF
XRPC
$221M
| $23.3K | ﹤0.01% |
+1,200
| New | +$26K |
|
|
FJET
6338
CALL
Starfighters Space Inc
FJET
$195M
| $23.3K | ﹤0.01% |
+2,000
| New | +$27.6K |
|
6339
PUT
Asbury Automotive
ABG
$4.31B
| $23.3K | ﹤0.01% |
100
| – | – |
|
6340
Galectin Therapeutics
GALT
$196M
| $23.2K | ﹤0.01% |
5,579
-61,761
| -92% | -$325K |
|
6341
Edgewell Personal Care
EPC
$1.25B
| $23.2K | ﹤0.01% |
1,361
+1,084
| +391% | +$20K |
|
|
BAND
6342
CALL
Bandwidth Inc
BAND
$1.26B
| $23.2K | ﹤0.01% |
1,500
-100
| -6% | -$1.52K |
|
6343
SK Telecom
SKM
$12.1B
| $23.1K | ﹤0.01% |
1,126
+592
| +111% | +$12.2K |
|
|
CRCG
6344
Leverage Shares 2X Long CRCL Daily ETF
CRCG
$82M
| $23.1K | ﹤0.01% |
889
+486
| +121% | +$26.6K |
|
6345
CALL
First Trust NASDAQ-100 Technology Index Fund
QTEC
$4.52B
| $23K | ﹤0.01% |
+100
| New | +$23.3K |
|
6346
CALL
Nexa Resources
NEXA
$1.7B
| $23K | ﹤0.01% |
+2,600
| New | +$16.9K |
|
6347
PUT
Atomera
ATOM
$200M
| $23K | ﹤0.01% |
10,400
-37,400
| -78% | -$113K |
|
6348
Ring Energy
REI
$315M
| $23K | ﹤0.01% |
26,416
-75
| -0.3% | -$71 |
|
6349
PUT
BTCS Inc
BTCS
$51.3M
| $23K | ﹤0.01% |
8,700
-19,000
| -69% | -$68.6K |
|
6350
iShares MSCI Global Metals & Mining Producers ETF
PICK
$2.22B
| $22.9K | ﹤0.01% |
+447
| New | +$21.1K |
|
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.