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 | Miscellaneous | 98.27% |
| 2 | Technology | 0.59% |
| 3 | Consumer Discretionary | 0.21% |
| 4 | Healthcare | 0.2% |
| 5 | Industrials | 0.18% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
501
NextEra Energy
NEE
$174B
| $23.6M | 0.01% |
293,398
+66,705
| +29% | +$5.52M |
|
502
Comcast
CMCSA
$94B
| $23.4M | 0.01% |
783,697
+646,575
| +472% | +$18.4M |
|
503
PUT
Cloudflare
NET
$99.3B
| $23.4M | 0.01% |
118,700
-78,700
| -40% | -$16.6M |
|
504
PUT
Lumentum
LITE
$79B
| $23.3M | 0.01% |
63,300
-49,800
| -44% | -$12.8M |
|
505
PUT
On Holding
ONON
$9.35B
| $23.2M | 0.01% |
499,700
+89,800
| +22% | +$3.87M |
|
506
PUT
Akamai
AKAM
$15.1B
| $23.1M | 0.01% |
265,100
+131,300
| +98% | +$10.8M |
|
507
CALL
Humana
HUM
$48.2B
| $23.1M | 0.01% |
90,000
-55,100
| -38% | -$14.4M |
|
508
CALL
Kroger
KR
$35.9B
| $22.9M | 0.01% |
366,900
-95,400
| -21% | -$6.24M |
|
509
PUT
EOG Resources
EOG
$76.2B
| $22.9M | 0.01% |
217,700
+57,900
| +36% | +$6.22M |
|
510
PUT
Lucid Motors
LCID
$1.84B
| $22.9M | 0.01% |
2,162,500
-1,018,700
| -32% | -$16.3M |
|
511
CALL
Viking Therapeutics
VKTX
$4.07B
| $22.7M | 0.01% |
646,200
+74,100
| +13% | +$2.63M |
|
512
PUT
Rocket Companies
RKT
$39.8B
| $22.5M | 0.01% |
1,163,200
-718,700
| -38% | -$12.9M |
|
513
PUT
Coherent
COHR
$55.2B
| $22.5M | 0.01% |
122,000
+2,100
| +2% | +$314K |
|
514
PUT
Xtrackers MSCI Emerging Markets Hedged Equity ETF
DBEM
$111M
| $22.5M | 0.01% |
682,500
-480,400
| -41% | -$15.2M |
|
515
PUT
Amphenol
APH
$204B
| $22.5M | 0.01% |
333,000
+20,200
| +6% | +$1.35M |
|
516
CALL
Analog Devices
ADI
$176B
| $22.4M | 0.01% |
82,500
-61,700
| -43% | -$15.5M |
|
517
PUT
Wynn Resorts
WYNN
$9.43B
| $22.4M | 0.01% |
185,800
-130,000
| -41% | -$16.1M |
|
518
PUT
NIO
NIO
$9.52B
| $22.4M | 0.01% |
4,383,000
-2,530,600
| -37% | -$15.6M |
|
519
TeraWulf
WULF
$8.24B
| $22.3M | 0.01% |
1,941,017
+1,078,795
| +125% | +$14.5M |
|
520
CALL
Insmed
INSM
$27.6B
| $22.3M | 0.01% |
128,100
-20,600
| -14% | -$3.76M |
|
521
CALL
AB InBev
BUD
$158B
| $22.3M | 0.01% |
347,700
+64,000
| +23% | +$3.97M |
|
522
PUT
Fortinet
FTNT
$115B
| $22.2M | 0.01% |
279,400
-32,300
| -10% | -$2.68M |
|
523
PUT
Corning
GLW
$133B
| $22.2M | 0.01% |
253,200
-110,500
| -30% | -$9.52M |
|
524
CALL
Linde
LIN
$220B
| $22.1M | 0.01% |
51,900
+26,300
| +103% | +$11.3M |
|
525
PUT
Lockheed Martin
LMT
$121B
| $22.1M | 0.01% |
45,700
-28,900
| -39% | -$13.8M |
|
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's Q4 2025 filing shows 1,476 new, 2,599 increased, 4,088 reduced and 2,184 closed positions. Its largest new stake was Western Digital: 341,762 shares worth $58.9M. The largest sale was NVIDIA, an estimated $262M.
By sector, the portfolio is most concentrated in Miscellaneous at 98% of assets, up from 98% a quarter earlier, followed by Technology and Consumer Discretionary.
- 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.