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 | |
|---|---|---|---|---|---|---|
1001
CALL
Ascendis Pharma A/S
ASND
$17.7B
| $7.91M | ﹤0.01% |
37,100
+2,600
| +8% | +$537K |
|
1002
CALL
Eastman Chemical
EMN
$8.14B
| $7.88M | ﹤0.01% |
123,400
+88,300
| +252% | +$5.44M |
|
1003
CALL
Pultegroup
PHM
$23.7B
| $7.87M | ﹤0.01% |
67,100
-6,800
| -9% | -$834K |
|
1004
PUT
Ciena
CIEN
$45.5B
| $7.83M | ﹤0.01% |
33,500
+10,000
| +43% | +$1.94M |
|
1005
CALL
Procore
PCOR
$8.81B
| $7.83M | ﹤0.01% |
107,700
+82,400
| +326% | +$6.09M |
|
1006
PUT
Viking Therapeutics
VKTX
$4.07B
| $7.81M | ﹤0.01% |
222,000
+92,300
| +71% | +$3.27M |
|
1007
CALL
HubSpot
HUBS
$12.3B
| $7.79M | ﹤0.01% |
19,400
-2,300
| -11% | -$953K |
|
1008
CALL
Teck Resources
TECK
$33.9B
| $7.77M | ﹤0.01% |
162,200
-81,700
| -33% | -$3.54M |
|
1009
CALL
Viavi Solutions
VIAV
$8.6B
| $7.77M | ﹤0.01% |
435,900
+77,200
| +22% | +$1.25M |
|
1010
CALL
Travere Therapeutics
TVTX
$6.15B
| $7.76M | ﹤0.01% |
203,200
-4,300
| -2% | -$140K |
|
1011
PUT
Keurig Dr Pepper
KDP
$44.3B
| $7.73M | ﹤0.01% |
275,900
+134,400
| +95% | +$3.69M |
|
1012
CALL
Crocs
CROX
$5.63B
| $7.72M | ﹤0.01% |
90,300
-126,200
| -58% | -$10.6M |
|
1013
CALL
SEALSQ Corp
LAES
$539M
| $7.72M | ﹤0.01% |
2,042,400
+911,400
| +81% | +$4.65M |
|
1014
CALL
BCE
BCE
$22.1B
| $7.72M | ﹤0.01% |
324,000
-82,200
| -20% | -$1.91M |
|
1015
CALL
AES
AES
$10.6B
| $7.71M | ﹤0.01% |
537,500
-63,700
| -11% | -$898K |
|
1016
PUT
Cencora
COR
$63.2B
| $7.7M | ﹤0.01% |
22,800
+10,700
| +88% | +$3.65M |
|
|
PPLT
1017
PUT
abrdn Physical Platinum Shares ETF
PPLT
$2.23B
| $7.7M | ﹤0.01% |
413,000
+125,000
| +43% | +$1.93M |
|
1018
CALL
Northrop Grumman
NOC
$73.2B
| $7.7M | ﹤0.01% |
13,500
+700
| +5% | +$406K |
|
|
CMA
1019
CALL
DELISTED
Comerica
CMA
| $7.68M | ﹤0.01% |
88,300
-112,800
| -56% | -$9.08M |
|
1020
PUT
Prologis
PLD
$131B
| $7.65M | ﹤0.01% |
59,900
-16,100
| -21% | -$2.01M |
|
1021
Ionis Pharmaceuticals
IONS
$9.65B
| $7.65M | ﹤0.01% |
96,647
-3,559
| -4% | -$268K |
|
1022
CALL
The Mosaic Company
MOS
$8.22B
| $7.63M | ﹤0.01% |
316,800
-53,200
| -14% | -$1.43M |
|
1023
PUT
ATI
ATI
$28.7B
| $7.63M | ﹤0.01% |
66,500
-83,100
| -56% | -$8.1M |
|
1024
PUT
Ally Financial
ALLY
$13.3B
| $7.62M | ﹤0.01% |
168,300
-154,100
| -48% | -$6.35M |
|
1025
CALL
Zillow
Z
$7.78B
| $7.61M | ﹤0.01% |
111,600
-74,500
| -40% | -$5.39M |
|
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.