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 | |
|---|---|---|---|---|---|---|
351
CALL
Constellation Energy
CEG
$98.2B
| $36.9M | 0.02% |
104,500
-47,200
| -31% | -$17.2M |
|
352
PUT
Affirm
AFRM
$24.8B
| $36.9M | 0.02% |
495,900
-170,200
| -26% | -$12.2M |
|
353
CALL
D-Wave Quantum
QBTS
$6.43B
| $36.7M | 0.02% |
1,403,400
+60,900
| +5% | +$1.77M |
|
354
CALL
American Airlines Group
AAL
$9.78B
| $36.7M | 0.02% |
2,393,200
-1,707,200
| -42% | -$23M |
|
|
SCHW
355
CALL
Charles Schwab
SCHW
$175B
| $36.5M | 0.02% |
365,700
-118,300
| -24% | -$11.2M |
|
356
CALL
Intuit
INTU
$77.8B
| $36.4M | 0.02% |
55,000
-53,800
| -49% | -$35.6M |
|
357
PUT
Kenvue
KVUE
$36.7B
| $36.4M | 0.02% |
2,109,600
-239,300
| -10% | -$3.91M |
|
358
CALL
Wynn Resorts
WYNN
$9.79B
| $36.4M | 0.02% |
302,400
+18,300
| +6% | +$2.26M |
|
359
PUT
Wayfair
W
$11.1B
| $36.1M | 0.02% |
359,800
-149,100
| -29% | -$14.3M |
|
360
PUT
Vistra
VST
$56.2B
| $36.1M | 0.02% |
223,900
-225,200
| -50% | -$41M |
|
361
PUT
United States Oil Fund
USO
$2.36B
| $35.9M | 0.02% |
519,500
-19,300
| -4% | -$1.36M |
|
362
CALL
Celestica
CLS
$38.6B
| $35.9M | 0.02% |
121,500
-46,200
| -28% | -$13.9M |
|
363
CALL
Nu Holdings
NU
$70.1B
| $35.5M | 0.02% |
2,117,900
-949,000
| -31% | -$15.3M |
|
|
364
CALL
Kenvue
KVUE
$36.7B
| $35.3M | 0.02% |
2,046,700
-2,517,700
| -55% | -$41.2M |
|
365
CALL
GE Aerospace
GE
$354B
| $35.3M | 0.02% |
114,600
-82,100
| -42% | -$24.7M |
|
366
PUT
Lowe's Companies
LOW
$115B
| $35.2M | 0.02% |
146,100
-4,900
| -3% | -$1.18M |
|
367
CALL
Cameco
CCJ
$39.4B
| $35.1M | 0.02% |
384,100
-92,000
| -19% | -$8.28M |
|
368
CALL
Ford
F
$57.5B
| $35.1M | 0.02% |
2,675,900
+477,500
| +22% | +$6.16M |
|
369
PUT
Blackrock
BLK
$164B
| $34.7M | 0.02% |
32,400
-5,200
| -14% | -$5.68M |
|
370
PUT
Gildan
GIL
$9.86B
| $34.7M | 0.02% |
+554,900
| New | +$33M |
|
371
CALL
Corning
GLW
$133B
| $34.3M | 0.02% |
391,400
-222,200
| -36% | -$19.1M |
|
372
PUT
SLB Ltd
SLB
$71.3B
| $34.2M | 0.02% |
892,200
-388,600
| -30% | -$14.1M |
|
|
373
Microsoft
MSFT
$2.9T
| $34.1M | 0.02% |
70,610
-387,699
| -85% | -$194M |
|
374
Palantir
PLTR
$299B
| $34M | 0.02% |
191,290
+128,521
| +205% | +$23.3M |
|
|
SCHW
375
PUT
Charles Schwab
SCHW
$175B
| $33.9M | 0.02% |
339,200
-166,600
| -33% | -$15.8M |
|
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 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.