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 | |
|---|---|---|---|---|---|---|
2851
Sonoco
SON
$5.77B
| $793K | ﹤0.01% |
18,165
-8,471
| -32% | -$351K |
|
|
OS
2852
PUT
DELISTED
OneStream Inc
OS
| $792K | ﹤0.01% |
43,100
-15,800
| -27% | -$301K |
|
|
LAR
2853
CALL
Lithium Argentina AG
LAR
$944M
| $791K | ﹤0.01% |
141,700
+106,500
| +303% | +$506K |
|
2854
PUT
Amplify Energy
AMPY
$156M
| $790K | ﹤0.01% |
172,900
-119,100
| -41% | -$593K |
|
2855
PUT
Farmers National Banc Corp
FMNB
$905M
| $790K | ﹤0.01% |
59,300
| – | – |
|
2856
POET Technologies
POET
$1.19B
| $790K | ﹤0.01% |
+124,733
| New | +$791K |
|
2857
CALL
Microvast
MVST
$262M
| $789K | ﹤0.01% |
281,700
-8,600
| -3% | -$35.9K |
|
|
PEW
2858
CALL
GrabAGun Digital Holdings
PEW
$72.3M
| $788K | ﹤0.01% |
261,900
+42,500
| +19% | +$170K |
|
2859
FTAI Infrastructure
FIP
$486M
| $788K | ﹤0.01% |
170,955
+82,506
| +93% | +$407K |
|
|
XIFR
2860
PUT
XPLR Infrastructure LP
XIFR
$1.18B
| $787K | ﹤0.01% |
78,700
-63,500
| -45% | -$615K |
|
2861
PUT
FuelCell Energy
FCEL
$1.67B
| $787K | ﹤0.01% |
107,600
-13,100
| -11% | -$107K |
|
|
SEMR
2862
CALL
DELISTED
Semrush
SEMR
| $786K | ﹤0.01% |
66,100
+60,300
| +1,040% | +$565K |
|
|
GES
2863
CALL
DELISTED
Guess Inc
GES
| $786K | ﹤0.01% |
46,900
+2,100
| +5% | +$35.5K |
|
2864
CALL
Vertex
VERX
$2.08B
| $785K | ﹤0.01% |
39,300
+38,300
| +3,830% | +$828K |
|
|
HPP
2865
CALL
Hudson Pacific Properties
HPP
$823M
| $784K | ﹤0.01% |
72,400
+70,500
| +3,711% | +$1.05M |
|
2866
CALL
PAR Technology
PAR
$678M
| $784K | ﹤0.01% |
21,600
+10,100
| +88% | +$364K |
|
2867
Cincinnati Financial
CINF
$28.6B
| $784K | ﹤0.01% |
4,798
+2,074
| +76% | +$336K |
|
2868
PUT
Helmerich & Payne
HP
$3.42B
| $783K | ﹤0.01% |
27,300
-4,100
| -13% | -$109K |
|
2869
PUT
Vanguard ESG US Corporate Bond ETF
VCEB
$1.18B
| $780K | ﹤0.01% |
10,400
+7,000
| +206% | +$448K |
|
|
OBE
2870
CALL
Obsidian Energy
OBE
$672M
| $780K | ﹤0.01% |
127,200
+100
| +0.1% | +$605 |
|
|
OPRA
2871
PUT
Opera Ltd
OPRA
$1.68B
| $779K | ﹤0.01% |
55,000
+4,500
| +9% | +$66.4K |
|
2872
CALL
loanDepot
LDI
$548M
| $779K | ﹤0.01% |
376,100
-412,400
| -52% | -$1.15M |
|
2873
RLX Technology
RLX
$2.47B
| $777K | ﹤0.01% |
333,276
+23,066
| +7% | +$55.3K |
|
2874
PUT
Fresenius Medical Care
FMS
$13.4B
| $777K | ﹤0.01% |
+32,600
| New | +$811K |
|
2875
CALL
Aon
AON
$78.7B
| $776K | ﹤0.01% |
2,200
-1,600
| -42% | -$559K |
|
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.