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 |
Apple
AAPL
|
+$70.1M |
| 2 |
iShares 20+ Year Treasury Bond ETF
TLT
|
+$46.6M |
| 3 |
Alphabet (Google) Class C
GOOG
|
+$37.4M |
| 4 |
Amazon
AMZN
|
+$37M |
| 5 |
Tesla
TSLA
|
+$28M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
Alibaba
BABA
|
+$41M |
| 2 |
Boeing
BA
|
+$27.8M |
| 3 |
Biogen
BIIB
|
+$18.9M |
| 4 |
SPDR Gold Trust
GLD
|
+$18.3M |
| 5 |
State Street SPDR Dow Jones Industrial Average ETF Trust
DIA
|
+$13.6M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Miscellaneous | 97.26% |
| 2 | Technology | 0.76% |
| 3 | Consumer Discretionary | 0.58% |
| 4 | Communication Services | 0.34% |
| 5 | Healthcare | 0.32% |
Similar funds
Simplex Trading's Q4 2019 Portfolio in Review
As of Q4 2019, Simplex Trading held 8,523 positions worth $45.7B, up 30% from $35.2B the previous quarter. Its ten largest holdings account for 39% of the portfolio.
Simplex Trading's Q4 2019 filing shows 1,277 new, 3,072 increased, 2,710 reduced and 1,251 closed positions. Its largest new stake was Apple: 1,090,316 shares worth $80M. The largest sale was Alibaba, an estimated $41M.
By sector, the portfolio is most concentrated in Miscellaneous at 97% of assets, down from 98% a quarter earlier, followed by Technology and Consumer Discretionary.
- Simplex Trading's largest Q4 2019 buy was Apple: 1,090,316 shares worth $80M.
- Simplex Trading added most to iShares 20+ Year Treasury Bond ETF in Q4 2019, an estimated $46.6M increase.
- Simplex Trading's biggest Q4 2019 reduction was Alibaba, cutting an estimated $41M.
- Simplex Trading fully exited Boeing in Q4 2019, selling an estimated $27.8M.
- Simplex Trading's ten largest holdings make up 39% of its $45.7B portfolio in Q4 2019.
- Simplex Trading opened 1,277 new positions and closed 1,251 in Q4 2019.
- Simplex Trading's portfolio value rose 30% quarter-over-quarter to $45.7B.
Based on Simplex Trading's 13F filing for Q4 2019, filed 5 Feb 2020.