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 |
Alphabet (Google) Class C
GOOG
|
+$40.1M |
| 2 |
Berkshire Hathaway Class B
BRK.B
|
+$12.5M |
| 3 |
Alibaba
BABA
|
+$10.5M |
| 4 |
State Street SPDR S&P 500 ETF Trust
SPY
|
+$9.89M |
| 5 |
Intel
INTC
|
+$9.83M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
Apple
AAPL
|
+$35.7M |
| 2 |
Gilead Sciences
GILD
|
+$32.3M |
| 3 |
Amazon
AMZN
|
+$29M |
| 4 |
Booking.com
BKNG
|
+$28.4M |
| 5 |
Baidu
BIDU
|
+$13.3M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Communication Services | 7.76% |
| 2 | Consumer Discretionary | 7.62% |
| 3 | Healthcare | 7.24% |
| 4 | Technology | 6.95% |
| 5 | Financials | 4.83% |
Similar funds
Simplex Trading's Q1 2015 Portfolio in Review
As of Q1 2015, Simplex Trading held 6,670 positions worth $860M, up 4.2% from $826M the previous quarter. Its ten largest holdings account for 15% of the portfolio.
Simplex Trading's Q1 2015 filing shows 1,973 new, 1,386 increased, 1,513 reduced and 1,643 closed positions. Its largest new stake was Alphabet (Google) Class C: 1,497,580 shares worth $41.4M. The largest sale was Apple, an estimated $35.7M.
By sector, the portfolio is most concentrated in Communication Services at 7.8% of assets, up from 4.8% a quarter earlier, followed by Consumer Discretionary and Healthcare.
- Simplex Trading's largest Q1 2015 buy was Alphabet (Google) Class C: 1,497,580 shares worth $41.4M.
- Simplex Trading added most to Alibaba in Q1 2015, an estimated $10.5M increase.
- Simplex Trading's biggest Q1 2015 reduction was Apple, cutting an estimated $35.7M.
- Simplex Trading fully exited Amazon in Q1 2015, selling an estimated $29M.
- Simplex Trading's ten largest holdings make up 15% of its $860M portfolio in Q1 2015.
- Simplex Trading opened 1,973 new positions and closed 1,643 in Q1 2015.
- Simplex Trading's portfolio value rose 4.2% quarter-over-quarter to $860M.
Based on Simplex Trading's 13F filing for Q1 2015, filed 21 Apr 2015.