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 |
Amazon
AMZN
|
+$45.9M |
| 2 |
iShares Russell 2000 ETF
IWM
|
+$30.1M |
| 3 |
TWX
Time Warner Inc
TWX
|
+$25.8M |
| 4 |
Booking.com
BKNG
|
+$22.5M |
| 5 |
Alphabet (Google) Class C
GOOG
|
+$17.7M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
State Street SPDR S&P 500 ETF Trust
SPY
|
+$43.6M |
| 2 |
Amgen
AMGN
|
+$33.2M |
| 3 |
Baidu
BIDU
|
+$19.3M |
| 4 |
Alphabet (Google) Class A
GOOGL
|
+$17.3M |
| 5 |
Micron Technology
MU
|
+$17.1M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Miscellaneous | 39.59% |
| 2 | Consumer Discretionary | 14.54% |
| 3 | Technology | 13.33% |
| 4 | Communication Services | 11.89% |
| 5 | Healthcare | 4.58% |
Similar funds
Simplex Trading's Q3 2017 Portfolio in Review
As of Q3 2017, Simplex Trading held 7,357 positions worth $2.45B, up 6.4% from $2.3B the previous quarter. Its ten largest holdings account for 24% of the portfolio.
Simplex Trading's Q3 2017 filing shows 1,313 new, 2,078 increased, 2,339 reduced and 1,500 closed positions. Its largest new stake was iShares Russell 2000 ETF: 214,170 shares worth $31.7M. The largest sale was State Street SPDR S&P 500 ETF Trust, an estimated $43.6M.
By sector, the portfolio is most concentrated in Miscellaneous at 40% of assets, down from 40% a quarter earlier, followed by Consumer Discretionary and Technology.
- Simplex Trading's largest Q3 2017 buy was iShares Russell 2000 ETF: 214,170 shares worth $31.7M.
- Simplex Trading added most to Amazon in Q3 2017, an estimated $45.9M increase.
- Simplex Trading's biggest Q3 2017 reduction was Baidu, cutting an estimated $19.3M.
- Simplex Trading fully exited State Street SPDR S&P 500 ETF Trust in Q3 2017, selling an estimated $43.6M.
- Simplex Trading's ten largest holdings make up 24% of its $2.45B portfolio in Q3 2017.
- Simplex Trading opened 1,313 new positions and closed 1,500 in Q3 2017.
- Simplex Trading's portfolio value rose 6.4% quarter-over-quarter to $2.45B.
Based on Simplex Trading's 13F filing for Q3 2017, filed 25 Oct 2017.