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 |
Tesla
TSLA
|
+$33.5M |
| 2 |
Netflix
NFLX
|
+$22.8M |
| 3 |
State Street SPDR Dow Jones Industrial Average ETF Trust
DIA
|
+$20.9M |
| 4 |
TWX
Time Warner Inc
TWX
|
+$18.3M |
| 5 |
Alibaba
BABA
|
+$15.2M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
Amazon
AMZN
|
+$71.1M |
| 2 |
Micron Technology
MU
|
+$43.8M |
| 3 |
Alphabet (Google) Class C
GOOG
|
+$26.3M |
| 4 |
Booking.com
BKNG
|
+$22.2M |
| 5 |
Boeing
BA
|
+$21.6M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Miscellaneous | 56% |
| 2 | Consumer Discretionary | 7.95% |
| 3 | Communication Services | 7.36% |
| 4 | Technology | 6.39% |
| 5 | Financials | 5.53% |
Similar funds
Simplex Trading's Q1 2018 Portfolio in Review
As of Q1 2018, Simplex Trading held 7,591 positions worth $2.27B, down 2.1% from $2.32B the previous quarter. Its ten largest holdings account for 18% of the portfolio.
Simplex Trading withdrew a net $319M in Q1 2018, closing 1,502 positions and reducing 2,267 holdings. Its most notable exit was Alphabet (Google) Class C, an estimated $26.3M position sold in full.
By sector, the portfolio is most concentrated in Miscellaneous at 56% of assets, up from 44% a quarter earlier, followed by Consumer Discretionary and Communication Services.
Against the trend, Simplex Trading opened a new position in Tesla worth $27.1M.
- Simplex Trading's largest Q1 2018 buy was Tesla: 1,525,035 shares worth $27.1M.
- Simplex Trading added most to Netflix in Q1 2018, an estimated $22.8M increase.
- Simplex Trading's biggest Q1 2018 reduction was Amazon, cutting an estimated $71.1M.
- Simplex Trading fully exited Alphabet (Google) Class C in Q1 2018, selling an estimated $26.3M.
- Simplex Trading's ten largest holdings make up 18% of its $2.27B portfolio in Q1 2018.
- Simplex Trading opened 1,643 new positions and closed 1,502 in Q1 2018.
- Simplex Trading's portfolio value fell 2.1% quarter-over-quarter to $2.27B.
Based on Simplex Trading's 13F filing for Q1 2018, filed 26 Apr 2018.