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 |
iShares Russell 2000 ETF
IWM
|
+$146M |
| 2 |
iShares 20+ Year Treasury Bond ETF
TLT
|
+$108M |
| 3 |
Apple
AAPL
|
+$62.9M |
| 4 |
Tesla
TSLA
|
+$51.9M |
| 5 |
Micron Technology
MU
|
+$39.5M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
State Street SPDR S&P 500 ETF Trust
SPY
|
+$108M |
| 2 |
Meta Platforms (Facebook)
META
|
+$104M |
| 3 |
Advanced Micro Devices
AMD
|
+$92.1M |
| 4 |
Amazon
AMZN
|
+$90.3M |
| 5 |
TSMC
TSM
|
+$82.9M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Miscellaneous | 98.28% |
| 2 | Technology | 0.76% |
| 3 | Consumer Discretionary | 0.21% |
| 4 | Communication Services | 0.19% |
| 5 | Healthcare | 0.15% |
Similar funds
Simplex Trading's Q2 2026 Portfolio in Review
As of Q2 2026, Simplex Trading held 10,638 positions worth $171B, up 14% from $149B the previous quarter. Its ten largest holdings account for 50% of the portfolio.
Simplex Trading's Q2 2026 filing shows 1,714 new, 3,712 increased, 3,486 reduced and 1,487 closed positions. Its largest new stake was Micron Technology: 52,682 shares worth $60.8M. The largest sale was State Street SPDR S&P 500 ETF Trust, an estimated $108M.
By sector, the portfolio is most concentrated in Miscellaneous at 98% of assets, down from 98% a quarter earlier, followed by Technology and Consumer Discretionary.
- Simplex Trading's largest Q2 2026 buy was Micron Technology: 52,682 shares worth $60.8M.
- Simplex Trading added most to iShares Russell 2000 ETF in Q2 2026, an estimated $146M increase.
- Simplex Trading's biggest Q2 2026 reduction was State Street SPDR S&P 500 ETF Trust, cutting an estimated $108M.
- Simplex Trading fully exited Intel in Q2 2026, selling an estimated $76.6M.
- Simplex Trading's ten largest holdings make up 50% of its $171B portfolio in Q2 2026.
- Simplex Trading opened 1,714 new positions and closed 1,487 in Q2 2026.
- Simplex Trading's portfolio value rose 14% quarter-over-quarter to $171B.
Based on Simplex Trading's 13F filing for Q2 2026, filed 12 Aug 2026.