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 | |
|---|---|---|---|---|---|---|
1426
CALL
VanEck Durable High Dividend ETF
DURA
$38.6M
| $4.17M | ﹤0.01% |
32,400
-7,200
| -18% | -$242K |
|
1427
CALL
Enbridge
ENB
$109B
| $4.16M | ﹤0.01% |
87,000
-1,800
| -2% | -$85.9K |
|
1428
PUT
Baker Hughes
BKR
$63B
| $4.16M | ﹤0.01% |
91,300
-26,300
| -22% | -$1.25M |
|
1429
PUT
Builders FirstSource
BLDR
$7.08B
| $4.16M | ﹤0.01% |
40,400
-16,300
| -29% | -$1.83M |
|
1430
CALL
Antero Midstream
AM
$10.7B
| $4.15M | ﹤0.01% |
233,300
+64,500
| +38% | +$1.16M |
|
1431
CALL
Crane Co
CR
$11.8B
| $4.15M | ﹤0.01% |
22,500
+18,400
| +449% | +$3.41M |
|
1432
CALL
PENN Entertainment
PENN
$2.29B
| $4.14M | ﹤0.01% |
281,000
-4,400
| -2% | -$68.6K |
|
1433
PUT
Teladoc Health
TDOC
$1.14B
| $4.14M | ﹤0.01% |
591,600
+110,100
| +23% | +$862K |
|
|
SKYT
1434
CALL
DELISTED
SkyWater Technology
SKYT
| $4.13M | ﹤0.01% |
227,400
-20,900
| -8% | -$363K |
|
|
GLXY
1435
PUT
Galaxy Digital Inc
GLXY
$5.12B
| $4.13M | ﹤0.01% |
184,500
-384,200
| -68% | -$11.9M |
|
1436
CALL
Tractor Supply
TSCO
$18.2B
| $4.12M | ﹤0.01% |
82,300
-8,000
| -9% | -$431K |
|
1437
CALL
Ball Corp
BALL
$16.6B
| $4.12M | ﹤0.01% |
77,700
+6,200
| +9% | +$305K |
|
1438
PUT
Opendoor
OPEN
$3.06B
| $4.1M | ﹤0.01% |
3,657,300
-2,554,687
| -41% | -$18.3M |
|
|
JMIA
1439
PUT
Jumia Technologies
JMIA
$974M
| $4.1M | ﹤0.01% |
328,600
-3,900
| -1% | -$45.1K |
|
1440
CALL
Harrow
HROW
$1.44B
| $4.1M | ﹤0.01% |
83,700
+64,200
| +329% | +$2.7M |
|
|
EH
1441
EHang Holdings
EH
$356M
| $4.09M | ﹤0.01% |
310,067
+51,397
| +20% | +$811K |
|
1442
CALL
Listed Funds Trust Roundhill Magnificent Seven ETF
MAGS
$4.26B
| $4.08M | ﹤0.01% |
91,600
+41,800
| +84% | +$2.76M |
|
1443
PUT
Trip.com Group
TCOM
$25.8B
| $4.08M | ﹤0.01% |
56,700
-36,100
| -39% | -$2.58M |
|
1444
CALL
Hawaiian Electric Industries
HE
$1.92B
| $4.06M | ﹤0.01% |
330,200
-219,700
| -40% | -$2.55M |
|
1445
CALL
Intellia Therapeutics
NTLA
$1.79B
| $4.06M | ﹤0.01% |
451,600
+185,800
| +70% | +$2.56M |
|
1446
CALL
Allstate
ALL
$65.6B
| $4.06M | ﹤0.01% |
19,500
+2,400
| +14% | +$491K |
|
1447
PUT
Wingstop
WING
$2.97B
| $4.05M | ﹤0.01% |
17,000
-11,700
| -41% | -$2.9M |
|
1448
CALL
Amprius Technologies
AMPX
$1.44B
| $4.04M | ﹤0.01% |
511,800
-252,300
| -33% | -$2.88M |
|
1449
PUT
Darden Restaurants
DRI
$24.6B
| $4.03M | ﹤0.01% |
21,900
-22,400
| -51% | -$4.08M |
|
1450
PUT
Pagaya Technologies
PGY
$1.92B
| $4.03M | ﹤0.01% |
201,900
-11,000
| -5% | -$280K |
|
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.