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% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | Held Since | |
|---|---|---|---|---|---|---|---|
6226
CALL
Rafael Holdings
RFL
$63.4M
| $53.8K | ﹤0.01% |
+16,400
| New | +$26.3K |
2026 Q2
0 quarters
|
|
6227
Community Health Systems
CYH
$422M
| $53.8K | ﹤0.01% |
+16,096
| New | +$47.4K |
2026 Q2
0 quarters
|
|
6228
PUT
Melco Resorts & Entertainment
MLCO
$1.47B
| $53.8K | ﹤0.01% |
10,200
+1,900
| +23% | +$10.6K |
2026 Q1
1 quarter
|
|
6229
Fidelity Solana Fund
FSOL
$130M
| $53.7K | ﹤0.01% |
6,203
+5,541
| +837% | +$52.8K |
2025 Q4
2 quarters
|
|
6230
Idexx Laboratories
IDXX
$44.2B
| $53.7K | ﹤0.01% |
102
+87
| +580% | +$48.8K |
2026 Q1
1 quarter
|
|
6231
PUT
MDA Space Ltd
MDA
$4.66B
| $53.7K | ﹤0.01% |
+1,300
| New | +$47.2K |
2026 Q2
0 quarters
|
|
6232
Dingdong
DDL
$431M
| $53.6K | ﹤0.01% |
+27,772
| New | +$68.9K |
2026 Q2
0 quarters
|
|
6233
PUT
Nexstar Media Group
NXST
$5.09B
| $53.6K | ﹤0.01% |
300
-200
| -40% | -$37.5K |
2023 Q1
13 quarters
|
|
6234
iRhythm Holdings
IRTC
$3.98B
| $53.5K | ﹤0.01% |
450
+268
| +147% | +$31.2K |
2026 Q1
1 quarter
|
|
6235
Daqo New Energy
DQ
$698M
| $53.5K | ﹤0.01% |
+3,997
| New | +$72.5K |
2026 Q2
0 quarters
|
|
6236
CALL
California Water Service
CWT
$2.94B
| $53.5K | ﹤0.01% |
1,100
+400
| +57% | +$18K |
2025 Q2
4 quarters
|
|
6237
WEBTOON Entertainment Inc
WBTN
$1.23B
| $53.5K | ﹤0.01% |
+4,684
| New | +$55.4K |
2026 Q2
0 quarters
|
|
6238
Commerce.com Inc Series 1
CMRC
$288M
| $53.3K | ﹤0.01% |
17,998
+9,747
| +118% | +$27.9K |
2025 Q3
3 quarters
|
|
6239
PUT
Profound Medical
PROF
$210M
| $53.2K | ﹤0.01% |
8,000
-600
| -7% | -$4.03K |
2025 Q1
5 quarters
|
|
6240
PUT
F&G Annuities & Life
FG
$2.7B
| $53.2K | ﹤0.01% |
2,000
-2,700
| -57% | -$73.9K |
2025 Q1
5 quarters
|
|
6241
CALL
Boston Beer
SAM
$2.01B
| $53.1K | ﹤0.01% |
300
-100
| -25% | -$20.3K |
2021 Q1
21 quarters
|
|
6242
CALL
DXC Technology
DXC
$2.53B
| $53.1K | ﹤0.01% |
6,000
+4,800
| +400% | +$49.7K |
2017 Q2
36 quarters
|
|
6243
CALL
Gentex
GNTX
$4.29B
| $53.1K | ﹤0.01% |
2,100
-11,300
| -84% | -$267K |
2017 Q4
34 quarters
|
|
6244
ProShares UltraPro Short 20+ Year Treasury
TTT
$19.3M
| $53.1K | ﹤0.01% |
803
+670
| +504% | +$45.8K |
2025 Q2
4 quarters
|
|
6245
CALL
NatWest
NWG
$66.7B
| $52.9K | ﹤0.01% |
3,000
-3,500
| -54% | -$56.3K |
2024 Q2
8 quarters
|
|
6246
CALL
Edgewise Therapeutics
EWTX
$4.25B
| $52.8K | ﹤0.01% |
1,300
+400
| +44% | +$13.8K |
2023 Q4
10 quarters
|
|
6247
Ibotta
IBTA
$975M
| $52.7K | ﹤0.01% |
1,543
+281
| +22% | +$9.38K |
2025 Q2
4 quarters
|
|
6248
PUT
AirSculpt Technologies
AIRS
$88.7M
| $52.6K | ﹤0.01% |
11,700
-3,500
| -23% | -$14.2K |
2026 Q1
1 quarter
|
|
|
6249
PUT
Idexx Laboratories
IDXX
$44.2B
| $52.6K | ﹤0.01% |
100
-200
| -67% | -$112K |
2016 Q1
41 quarters
|
|
6250
Goldman Sachs ETF Trust Goldman Sachs S&P 500 Premium Income ETF
GPIX
$6.33B
| $52.6K | ﹤0.01% |
+947
| New | +$51.3K |
2026 Q2
0 quarters
|
|
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.