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 | |
|---|---|---|---|---|---|---|
3976
PUT
Immunovant
IMVT
$8.02B
| $257K | ﹤0.01% |
10,100
-5,000
| -33% | -$111K |
|
|
CAI
3977
CALL
Caris Life Sciences
CAI
$4.37B
| $256K | ﹤0.01% |
9,500
+4,800
| +102% | +$135K |
|
3978
CALL
Aspen Aerogels
ASPN
$341M
| $256K | ﹤0.01% |
90,500
-5,500
| -6% | -$28.4K |
|
3979
CALL
Moody's
MCO
$83.8B
| $255K | ﹤0.01% |
500
-600
| -55% | -$293K |
|
|
ETHW
3980
PUT
Bitwise Ethereum ETF
ETHW
$199M
| $255K | ﹤0.01% |
12,000
+10,900
| +991% | +$270K |
|
3981
PUT
BlackSky Technology
BKSY
$847M
| $255K | ﹤0.01% |
13,600
-11,300
| -45% | -$230K |
|
|
AVGX
3982
Defiance Daily Target 2X Long AVGO ETF
AVGX
$233M
| $255K | ﹤0.01% |
5,438
-5,480
| -50% | -$294K |
|
3983
PUT
Fastly Inc
FSLY
$3.28B
| $255K | ﹤0.01% |
25,000
-25,900
| -51% | -$255K |
|
3984
VanEck Pharmaceutical ETF
PPH
$982M
| $254K | ﹤0.01% |
+2,463
| New | +$240K |
|
3985
CALL
EyePoint Inc
EYPT
$1.02B
| $254K | ﹤0.01% |
13,900
-10,800
| -44% | -$153K |
|
3986
CALL
Arqit Quantum
ARQQ
$272M
| $254K | ﹤0.01% |
11,600
-2,700
| -19% | -$93.4K |
|
|
SY
3987
PUT
So-Young International
SY
$192M
| $253K | ﹤0.01% |
99,000
-50,400
| -34% | -$164K |
|
3988
PUT
TC Energy
TRP
$69.9B
| $253K | ﹤0.01% |
4,600
-27,300
| -86% | -$1.46M |
|
3989
CALL
Arcos Dorados Holdings
ARCO
$1.75B
| $252K | ﹤0.01% |
34,400
+27,400
| +391% | +$197K |
|
|
RNAM
3990
CALL
DELISTED
Avidity Biosciences
RNAM
| $252K | ﹤0.01% |
3,500
-38,000
| -92% | -$2.45M |
|
3991
American Electric Power
AEP
$70.5B
| $252K | ﹤0.01% |
2,189
-2,895
| -57% | -$342K |
|
3992
CALL
Valley National Bancorp
VLY
$7.9B
| $252K | ﹤0.01% |
21,600
+500
| +2% | +$5.55K |
|
|
MDLN
3993
PUT
Medline Inc
MDLN
$33.8B
| $252K | ﹤0.01% |
+6,000
| New | +$253K |
|
3994
CALL
Procept Biorobotics
PRCT
$1.02B
| $252K | ﹤0.01% |
8,000
-6,300
| -44% | -$209K |
|
|
CGAU
3995
Centerra Gold
CGAU
$3.41B
| $251K | ﹤0.01% |
17,498
-158,815
| -90% | -$1.99M |
|
3996
Mistras Group
MG
$476M
| $250K | ﹤0.01% |
19,795
-16,544
| -46% | -$187K |
|
|
BLD
3997
CALL
DELISTED
TopBuild
BLD
| $250K | ﹤0.01% |
600
+500
| +500% | +$214K |
|
|
3998
PUT
EyePoint Inc
EYPT
$1.02B
| $250K | ﹤0.01% |
13,700
-20,300
| -60% | -$288K |
|
3999
PUT
Chord Energy
CHRD
$7.63B
| $250K | ﹤0.01% |
2,700
-14,600
| -84% | -$1.35M |
|
|
KDK
4000
PUT
Kodiak AI
KDK
$788M
| $250K | ﹤0.01% |
+22,900
| New | +$183K |
|
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.