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 |
NVIDIA
NVDA
|
+$172M |
| 2 |
Apple
AAPL
|
+$156M |
| 3 |
Broadcom
AVGO
|
+$101M |
| 4 |
State Street SPDR S&P 500 ETF Trust
SPY
|
+$57.2M |
| 5 |
UnitedHealth
UNH
|
+$55.1M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
iShares 20+ Year Treasury Bond ETF
TLT
|
+$140M |
| 2 |
Amazon
AMZN
|
+$47.9M |
| 3 |
Netflix
NFLX
|
+$38.3M |
| 4 |
TSMC
TSM
|
+$37.3M |
| 5 |
Pfizer
PFE
|
+$36.9M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 0.74% |
| 2 | Communication Services | 0.19% |
| 3 | Consumer Discretionary | 0.18% |
| 4 | Healthcare | 0.17% |
| 5 | Financials | 0.14% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
4826
CALL
Mirum Pharmaceuticals
MIRM
$6.56B
| $147K | ﹤0.01% |
2,900
-200
| -6% | -$8.9K |
|
|
MURA
4827
CALL
DELISTED
Mural Oncology
MURA
| $147K | ﹤0.01% |
59,700
+57,400
| +2,496% | +$135K |
|
4828
PUT
Microvision
MVIS
$84.8M
| $147K | ﹤0.01% |
129,000
-74,500
| -37% | -$86K |
|
4829
CALL
Neonode
NEON
$12.6M
| $147K | ﹤0.01% |
5,800
-4,300
| -43% | -$51.3K |
|
4830
New Oriental
EDU
$9.32B
| $146K | ﹤0.01% |
2,715
-1,715
| -39% | -$81.4K |
|
4831
CALL
Fortrea Holdings
FTRE
$1.93B
| $146K | ﹤0.01% |
29,700
+18,400
| +163% | +$98.9K |
|
|
NXDR
4832
Nextdoor Holdings
NXDR
$885M
| $146K | ﹤0.01% |
88,114
+81,302
| +1,194% | +$123K |
|
4833
CALL
Portland General Electric
POR
$5.82B
| $146K | ﹤0.01% |
3,600
-6,100
| -63% | -$256K |
|
|
FLNA
4834
PUT
Filana Therapeutics
FLNA
$42M
| $146K | ﹤0.01% |
81,200
+10,400
| +15% | +$18.5K |
|
4835
CALL
SFL Corp
SFL
$1.61B
| $146K | ﹤0.01% |
17,600
-1,600
| -8% | -$13.3K |
|
4836
PUT
Suburban Propane Partners
SPH
$1.21B
| $146K | ﹤0.01% |
7,900
-600
| -7% | -$11.7K |
|
4837
CALL
TriNet
TNET
$3.23B
| $146K | ﹤0.01% |
2,000
| – | – |
|
4838
ProShares UltraPro S&P 500
UPRO
$4.89B
| $146K | ﹤0.01% |
1,599
-28,961
| -95% | -$2.15M |
|
4839
Xperi
XPER
$364M
| $146K | ﹤0.01% |
18,472
+10,871
| +143% | +$81.9K |
|
4840
CALL
Amneal Pharmaceuticals
AMRX
$6.1B
| $145K | ﹤0.01% |
18,000
-7,800
| -30% | -$58.8K |
|
4841
CALL
M/I Homes
MHO
$3.95B
| $145K | ﹤0.01% |
1,300
-4,300
| -77% | -$467K |
|
4842
CALL
N-able
NABL
$844M
| $145K | ﹤0.01% |
+18,000
| New | +$134K |
|
4843
CALL
Outset Medical
OM
$86.4M
| $145K | ﹤0.01% |
7,600
-61,700
| -89% | -$963K |
|
4844
Pacific Biosciences
PACB
$435M
| $145K | ﹤0.01% |
117,525
+116,763
| +15,323% | +$135K |
|
4845
CALL
PAR Technology
PAR
$716M
| $145K | ﹤0.01% |
2,100
+1,100
| +110% | +$68.7K |
|
4846
CALL
Solid Biosciences
SLDB
$792M
| $145K | ﹤0.01% |
29,900
-11,400
| -28% | -$40.3K |
|
4847
PUT
Woodside Energy
WDS
$44.2B
| $145K | ﹤0.01% |
9,400
+8,700
| +1,243% | +$122K |
|
|
ACLX
4848
CALL
DELISTED
Arcellx
ACLX
| $144K | ﹤0.01% |
2,200
-5,100
| -70% | -$318K |
|
|
ARIS
4849
CALL
DELISTED
Aris Water Solutions
ARIS
| $144K | ﹤0.01% |
6,100
-7,600
| -55% | -$188K |
|
4850
Capital One
COF
$128B
| $144K | ﹤0.01% |
+680
| New | +$127K |
|
Similar funds
Simplex Trading's Q2 2025 Portfolio in Review
As of Q2 2025, Simplex Trading held 10,048 positions worth $175B, up 12% from $156B the previous quarter. Its ten largest holdings account for 47% of the portfolio.
Simplex Trading withdrew a net $10.5B in Q2 2025, closing 1,431 positions and reducing 3,590 holdings. Its most notable exit was Constellation Energy, an estimated $35.8M position sold in full.
By sector, the portfolio is most concentrated in Technology at 0.74% of assets, up from 0.41% a quarter earlier, followed by Communication Services and Consumer Discretionary.
Against the trend, Simplex Trading opened a new position in State Street SPDR S&P 500 ETF Trust worth $61.9M.
- Simplex Trading's largest Q2 2025 buy was State Street SPDR S&P 500 ETF Trust: 100,129 shares worth $61.9M.
- Simplex Trading added most to NVIDIA in Q2 2025, an estimated $172M increase.
- Simplex Trading's biggest Q2 2025 reduction was iShares 20+ Year Treasury Bond ETF, cutting an estimated $140M.
- Simplex Trading fully exited Constellation Energy in Q2 2025, selling an estimated $35.8M.
- Simplex Trading's ten largest holdings make up 47% of its $175B portfolio in Q2 2025.
- Simplex Trading opened 1,525 new positions and closed 1,431 in Q2 2025.
- Simplex Trading's portfolio value rose 12% quarter-over-quarter to $175B.
Based on Simplex Trading's 13F filing for Q2 2025, filed 5 Aug 2025.