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 | |
|---|---|---|---|---|---|---|
426
CALL
Cloudflare
NET
$99.3B
| $29.2M | 0.02% |
148,100
-21,400
| -13% | -$4.53M |
|
427
PUT
Nu Holdings
NU
$74.2B
| $29.2M | 0.02% |
1,742,000
+45,200
| +3% | +$726K |
|
428
PUT
Capital One
COF
$135B
| $29.1M | 0.02% |
120,000
-66,600
| -36% | -$14.8M |
|
429
Freeport-McMoran
FCX
$104B
| $28.7M | 0.02% |
565,970
+118,759
| +27% | +$5.15M |
|
430
PUT
Regeneron Pharmaceuticals
REGN
$85.2B
| $28.7M | 0.02% |
37,200
-12,600
| -25% | -$8.56M |
|
431
PUT
Analog Devices
ADI
$176B
| $28.5M | 0.02% |
105,200
+24,600
| +31% | +$6.18M |
|
432
CALL
Enterprise Products Partners
EPD
$84.1B
| $28.5M | 0.02% |
887,500
+255,800
| +40% | +$8.09M |
|
433
CALL
Agnico Eagle Mines
AEM
$104B
| $28.4M | 0.02% |
167,800
-165,300
| -50% | -$27.8M |
|
434
CALL
Vale
VALE
$65B
| $28.4M | 0.02% |
2,176,700
-1,567,600
| -42% | -$19M |
|
435
PUT
DoorDash
DASH
$91.7B
| $28.3M | 0.02% |
124,800
-134,600
| -52% | -$31.6M |
|
436
PUT
Sunrun
RUN
$2.14B
| $28.2M | 0.02% |
1,531,700
-169,700
| -10% | -$3.25M |
|
437
CALL
Danaher
DHR
$146B
| $28M | 0.02% |
122,700
-18,200
| -13% | -$4M |
|
438
CALL
PG&E
PCG
$31.5B
| $28M | 0.02% |
1,740,300
-1,881,900
| -52% | -$30.1M |
|
439
PUT
Southwest Airlines
LUV
$19.4B
| $28M | 0.02% |
676,400
-504,200
| -43% | -$17.6M |
|
440
VanEck Semiconductor ETF
SMH
$69B
| $28M | 0.02% |
+77,626
| New | +$27.2M |
|
441
Rocket Lab Corp
RKLB
$41.1B
| $27.9M | 0.02% |
+400,110
| New | +$22.9M |
|
442
Booking.com
BKNG
$145B
| $27.5M | 0.02% |
128,600
-210,200
| -62% | -$43.3M |
|
443
CALL
IonQ
IONQ
$16B
| $27.4M | 0.02% |
609,800
-346,900
| -36% | -$19.4M |
|
444
CALL
Gilead Sciences
GILD
$187B
| $27.3M | 0.02% |
222,400
-48,700
| -18% | -$5.92M |
|
445
CALL
Abbott
ABT
$187B
| $27.2M | 0.02% |
217,300
-103,800
| -32% | -$13.2M |
|
446
PUT
Hims & Hers Health
HIMS
$6.47B
| $27.1M | 0.02% |
835,800
-724,200
| -46% | -$31M |
|
447
CALL
Kraft Heinz
KHC
$29.5B
| $27.1M | 0.02% |
1,118,400
-753,700
| -40% | -$18.8M |
|
|
AXON
448
CALL
Axon Enterprise
AXON
$41.9B
| $27M | 0.02% |
47,500
+13,700
| +41% | +$8.5M |
|
449
PUT
Halliburton
HAL
$30.9B
| $26.8M | 0.02% |
946,700
-231,700
| -20% | -$6.12M |
|
450
CALL
W.W. Grainger
GWW
$62.4B
| $26.7M | 0.02% |
26,500
+8,300
| +46% | +$8.05M |
|
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.