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 | |
|---|---|---|---|---|---|---|
3601
Black Stone Minerals
BSM
$3.14B
| $373K | ﹤0.01% |
28,072
+25,027
| +822% | +$338K |
|
3602
Hexcel
HXL
$8.3B
| $373K | ﹤0.01% |
5,047
+3,891
| +337% | +$275K |
|
3603
PUT
Korea Electric Power
KEP
$14.9B
| $373K | ﹤0.01% |
22,600
+13,300
| +143% | +$211K |
|
3604
CALL
Perion Network
PERI
$378M
| $373K | ﹤0.01% |
38,900
+12,000
| +45% | +$117K |
|
3605
CALL
Gold Royalty Corp
GROY
$598M
| $372K | ﹤0.01% |
92,100
+13,100
| +17% | +$50.1K |
|
|
AGNT
3606
CALL
AGNT Inc
AGNT
$661M
| $372K | ﹤0.01% |
41,100
-9,200
| -18% | -$97.2K |
|
|
BBBY
3607
PUT
Bed Bath & Beyond
BBBY
$503M
| $371K | ﹤0.01% |
400,200
-121,860
| -23% | -$884K |
|
3608
PUT
FerroAtlántica
GSM
$628M
| $371K | ﹤0.01% |
79,900
-198,700
| -71% | -$917K |
|
3609
PUT
Cactus
WHD
$3.69B
| $370K | ﹤0.01% |
8,100
+200
| +3% | +$8.36K |
|
|
AIRL
3610
CALL
DELISTED
Themes Airlines ETF
AIRL
| $370K | ﹤0.01% |
18,300
+7,800
| +74% | +$158K |
|
3611
PUT
American Homes 4 Rent
AMH
$12.2B
| $369K | ﹤0.01% |
11,500
-700
| -6% | -$22.4K |
|
3612
Direxion Daily Junior Gold Miners Index Bear 2X ETF
JDST
$31.1M
| $369K | ﹤0.01% |
+7,007
| New | +$514K |
|
3613
Playtika
PLTK
$1.51B
| $368K | ﹤0.01% |
93,083
+843
| +0.9% | +$3.3K |
|
3614
CALL
Ecolab
ECL
$79.6B
| $368K | ﹤0.01% |
1,400
-14,800
| -91% | -$3.94M |
|
3615
CALL
SBA Communications
SBAC
$18.6B
| $368K | ﹤0.01% |
1,900
-9,000
| -83% | -$1.74M |
|
3616
PUT
Vuzix
VUZI
$187M
| $367K | ﹤0.01% |
97,100
+42,900
| +79% | +$135K |
|
3617
News Corp Class A
NWSA
$15.3B
| $366K | ﹤0.01% |
+14,012
| New | +$368K |
|
3618
Vanguard S&P 500 Growth ETF
VOOG
$25.2B
| $365K | ﹤0.01% |
+4,932
| New | +$363K |
|
|
SKE
3619
PUT
Skeena Resources
SKE
$3.28B
| $365K | ﹤0.01% |
15,400
-9,400
| -38% | -$185K |
|
3620
Equity Residential
EQR
$25.5B
| $364K | ﹤0.01% |
5,778
-15,912
| -73% | -$976K |
|
|
BDN
3621
PUT
Brandywine Realty Trust
BDN
$521M
| $364K | ﹤0.01% |
124,700
+92,900
| +292% | +$316K |
|
3622
Enovis
ENOV
$1.7B
| $364K | ﹤0.01% |
13,659
+10,842
| +385% | +$320K |
|
3623
CALL
Eve Holding
EVEX
$853M
| $363K | ﹤0.01% |
91,100
+70,200
| +336% | +$309K |
|
3624
CALL
TC Energy
TRP
$70.5B
| $363K | ﹤0.01% |
6,600
-40,700
| -86% | -$2.17M |
|
3625
CALL
FB Financial Corp
FBK
$2.98B
| $363K | ﹤0.01% |
6,500
+700
| +12% | +$39.1K |
|
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.