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 | |
|---|---|---|---|---|---|---|
6851
LG Display
LPL
$3.02B
| $12.3K | ﹤0.01% |
2,919
-15,856
| -84% | -$74K |
|
6852
VEON
VEON
$3.68B
| $12.2K | ﹤0.01% |
233
-666
| -74% | -$33.7K |
|
6853
CALL
NMI Holdings
NMIH
$3.4B
| $12.2K | ﹤0.01% |
300
-2,600
| -90% | -$98.3K |
|
6854
Andersons Inc
ANDE
$2.45B
| $12.2K | ﹤0.01% |
230
-1,669
| -88% | -$81.7K |
|
|
BSCI
6855
CALL
DELISTED
Invesco BulletShares 2018 Corporate Bond ETF
BSCI
| $12.2K | ﹤0.01% |
200
| – | – |
|
6856
CALL
Kontoor Brands
KTB
$4.58B
| $12.2K | ﹤0.01% |
+200
| New | +$14.8K |
|
6857
International Seaways
INSW
$4.75B
| $12.2K | ﹤0.01% |
+251
| New | +$12.4K |
|
|
NBP
6858
NovaBridge Biosciences American Depositary Shares
NBP
$187M
| $12.2K | ﹤0.01% |
+3,060
| New | +$13.5K |
|
6859
Fidelity Enhanced Large Cap Growth ETF
FELG
$5.43B
| $12.2K | ﹤0.01% |
292
-8
| -3% | -$333 |
|
6860
Direxion Daily AMZN Bull 2X ETF
AMZU
$358M
| $12.2K | ﹤0.01% |
348
-6,917
| -95% | -$252K |
|
6861
CALL
CuriosityStream
CURI
$143M
| $12.2K | ﹤0.01% |
3,200
-11,600
| -78% | -$51.7K |
|
6862
Financial Institutions
FISI
$808M
| $12.2K | ﹤0.01% |
+390
| New | +$11.5K |
|
6863
PUT
Pulmonx
LUNG
$65.9M
| $12.2K | ﹤0.01% |
5,500
+2,800
| +104% | +$5.26K |
|
6864
Xperi
XPER
$362M
| $12.1K | ﹤0.01% |
2,072
-29,021
| -93% | -$182K |
|
6865
CALL
Silgan Holdings
SLGN
$4.26B
| $12.1K | ﹤0.01% |
300
+100
| +50% | +$4.06K |
|
6866
CALL
908 Devices
MASS
$314M
| $12.1K | ﹤0.01% |
2,300
-6,100
| -73% | -$42.6K |
|
6867
PUT
ArriVent BioPharma
AVBP
$1.4B
| $12.1K | ﹤0.01% |
600
-20,600
| -97% | -$429K |
|
|
GXRP
6868
Grayscale XRP Trust ETF
GXRP
$50.4M
| $12.1K | ﹤0.01% |
+340
| New | +$13.2K |
|
|
CHCT
6869
Community Healthcare Trust
CHCT
$526M
| $12.1K | ﹤0.01% |
+735
| New | +$11K |
|
6870
CALL
Everspin Technologies
MRAM
$344M
| $12.1K | ﹤0.01% |
1,300
-3,000
| -70% | -$28.5K |
|
6871
CALL
Savara
SVRA
$1.11B
| $12.1K | ﹤0.01% |
2,000
+200
| +11% | +$980 |
|
6872
iShares US Consumer Staples ETF
IYK
$1.39B
| $12K | ﹤0.01% |
+180
| New | +$12.2K |
|
|
RWT
6873
Redwood Trust
RWT
$578M
| $12K | ﹤0.01% |
+2,178
| New | +$12K |
|
6874
CALL
TFS Financial
TFSL
$5.31B
| $12K | ﹤0.01% |
+900
| New | +$12.3K |
|
|
AFCG
6875
PUT
AFC Gamma
AFCG
$60.9M
| $12K | ﹤0.01% |
4,200
+3,900
| +1,300% | +$12.4K |
|
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.