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 | |
|---|---|---|---|---|---|---|
7876
NN Inc
NNBR
$261M
| $1.75K | ﹤0.01% |
1,364
-2,473
| -64% | -$3.78K |
|
7877
PUT
Stoneridge
SRI
$208M
| $1.74K | ﹤0.01% |
+300
| New | +$1.89K |
|
7878
PUT
AdvanSix
ASIX
$551M
| $1.73K | ﹤0.01% |
100
-1,000
| -91% | -$17.5K |
|
7879
PUT
Fortrea Holdings
FTRE
$1.96B
| $1.73K | ﹤0.01% |
100
-2,900
| -97% | -$35.8K |
|
7880
CALL
Lifezone Metals
LZM
$291M
| $1.71K | ﹤0.01% |
+400
| New | +$1.81K |
|
7881
ReposiTrak
TRAK
$159M
| $1.71K | ﹤0.01% |
+138
| New | +$1.96K |
|
|
NAVN
7882
CALL
Navan Inc
NAVN
$6.7B
| $1.71K | ﹤0.01% |
+100
| New | +$1.59K |
|
7883
CALL
Edgewell Personal Care
EPC
$1.3B
| $1.71K | ﹤0.01% |
100
| – | – |
|
7884
ProShares Short Russell2000
RWM
$131M
| $1.7K | ﹤0.01% |
104
-100,913
| -100% | -$1.67M |
|
7885
CALL
Heron Therapeutics
HRTX
$92M
| $1.69K | ﹤0.01% |
1,300
-5,200
| -80% | -$6.42K |
|
|
VENU
7886
CALL
Venu Holding Corp
VENU
$133M
| $1.68K | ﹤0.01% |
+200
| New | +$2.22K |
|
7887
Amplify CEF High Income ETF
YYY
$724M
| $1.68K | ﹤0.01% |
146
+136
| +1,360% | +$1.59K |
|
7888
PUT
Quince Therapeutics
QNCX
$18.9M
| $1.68K | ﹤0.01% |
+3
| New | +$1.51K |
|
|
SMHX
7889
VanEck Fabless Semiconductor ETF
SMHX
$241M
| $1.67K | ﹤0.01% |
+44
| New | +$1.71K |
|
|
INV
7890
CALL
Innventure Inc
INV
$249M
| $1.67K | ﹤0.01% |
+400
| New | +$1.68K |
|
|
UCTT
7891
Ultra Clean Holdings
UCTT
$3.47B
| $1.67K | ﹤0.01% |
66
-669
| -91% | -$17.8K |
|
|
PDM
7892
PUT
Piedmont Realty Trust
PDM
$1.2B
| $1.67K | ﹤0.01% |
+200
| New | +$1.67K |
|
7893
Quest Resource Holding
QRHC
$28.2M
| $1.66K | ﹤0.01% |
+890
| New | +$1.51K |
|
|
SNOY
7894
YieldMax SNOW Option Income Strategy ETF
SNOY
$57.9M
| $1.65K | ﹤0.01% |
+135
| New | +$1.93K |
|
|
CODX
7895
Co-Diagnostics
CODX
$5.2M
| $1.64K | ﹤0.01% |
325
-306
| -48% | -$3.33K |
|
7896
CALL
Ponce Financial Group
PDLB
$496M
| $1.64K | ﹤0.01% |
+100
| New | +$1.54K |
|
7897
Ultrapar
UGP
$6.74B
| $1.63K | ﹤0.01% |
433
-2,245
| -84% | -$8.88K |
|
7898
Envela
ELA
$555M
| $1.62K | ﹤0.01% |
+121
| New | +$1.26K |
|
7899
CALL
Paysafe
PSFE
$463M
| $1.62K | ﹤0.01% |
200
-1,000
| -83% | -$9.69K |
|
7900
CALL
WidePoint Corp
WYY
$99.6M
| $1.61K | ﹤0.01% |
300
-13,900
| -98% | -$86.5K |
|
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.