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 |
GE Aerospace
GE
|
+$36M |
| 2 |
Advanced Micro Devices
AMD
|
+$19.4M |
| 3 |
iShares MSCI EAFE ETF
EFA
|
+$10.2M |
| 4 |
Micron Technology
MU
|
+$6.31M |
| 5 |
Alibaba
BABA
|
+$6.19M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
NVIDIA
NVDA
|
+$25.9M |
| 2 |
SPDR Gold Trust
GLD
|
+$15.3M |
| 3 |
Amazon
AMZN
|
+$9.53M |
| 4 |
State Street SPDR S&P 500 ETF Trust
SPY
|
+$9.03M |
| 5 |
State Street Technology Select Sector SPDR ETF
XLK
|
+$7.73M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 0.49% |
| 2 | Consumer Discretionary | 0.39% |
| 3 | Communication Services | 0.27% |
| 4 | Healthcare | 0.25% |
| 5 | Financials | 0.25% |
Similar funds
Simplex Trading's Q3 2021 Portfolio in Review
As of Q3 2021, Simplex Trading held 10,062 positions worth $107B, up 3.4% from $104B the previous quarter. Its ten largest holdings account for 41% of the portfolio.
Trading was light in Q3 2021: portfolio turnover was 3.5%. Simplex Trading opened 86 new positions and exited 271, leaving the 10,062-position portfolio largely intact.
By sector, the portfolio is most concentrated in Technology at 0.49% of assets, up from 0.47% a quarter earlier, followed by Consumer Discretionary and Communication Services.
- Simplex Trading's largest Q3 2021 buy was Olo Inc: 143,230 shares worth $4.91M.
- Simplex Trading added most to GE Aerospace in Q3 2021, an estimated $36M increase.
- Simplex Trading's biggest Q3 2021 reduction was NVIDIA, cutting an estimated $25.9M.
- Simplex Trading fully exited Amazon in Q3 2021, selling an estimated $9.53M.
- Simplex Trading's ten largest holdings make up 41% of its $107B portfolio in Q3 2021.
- Simplex Trading opened 86 new positions and closed 271 in Q3 2021.
- Simplex Trading's portfolio value rose 3.4% quarter-over-quarter to $107B.
Based on Simplex Trading's 13F filing for Q3 2021, filed 28 Oct 2021.