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 | |
|---|---|---|---|---|---|---|
851
PUT
AGNC Investment
AGNC
$12.2B
| $10.6M | 0.01% |
1,155,500
-73,000
| -6% | -$653K |
|
852
CALL
C3.ai
AI
$1.23B
| $10.6M | 0.01% |
431,800
+99,600
| +30% | +$2.28M |
|
853
PUT
Carpenter Technology
CRS
$29.4B
| $10.6M | 0.01% |
38,300
+28,800
| +303% | +$6.28M |
|
854
PUT
Insmed
INSM
$23B
| $10.6M | 0.01% |
105,000
+89,900
| +595% | +$6.87M |
|
855
PUT
LyondellBasell Industries
LYB
$20.1B
| $10.5M | 0.01% |
182,300
-6,800
| -4% | -$396K |
|
856
CALL
Progressive
PGR
$120B
| $10.5M | 0.01% |
39,500
+3,200
| +9% | +$877K |
|
857
CALL
General Mills
GIS
$19.2B
| $10.5M | 0.01% |
203,400
+9,500
| +5% | +$524K |
|
858
Moderna
MRNA
$22.6B
| $10.5M | 0.01% |
381,787
+190,557
| +100% | +$5.02M |
|
859
PUT
Intercontinental Exchange
ICE
$80.9B
| $10.5M | 0.01% |
57,400
-2,000
| -3% | -$344K |
|
860
PUT
Kraft Heinz
KHC
$30.3B
| $10.5M | 0.01% |
785,700
+310,400
| +65% | +$8.62M |
|
861
PUT
Builders FirstSource
BLDR
$7.51B
| $10.5M | 0.01% |
90,000
+52,800
| +142% | +$6.09M |
|
862
PUT
NIO
NIO
$11.5B
| $10.5M | 0.01% |
3,059,000
+162,200
| +6% | +$604K |
|
863
PUT
Skyworks Solutions
SWKS
$9.07B
| $10.5M | 0.01% |
140,700
-33,100
| -19% | -$2.21M |
|
864
Mercado Libre
MELI
$90.1B
| $10.5M | 0.01% |
4,010
+214
| +6% | +$500K |
|
865
Citigroup
C
$221B
| $10.5M | 0.01% |
123,006
-396,031
| -76% | -$28.6M |
|
|
CYBR
866
CALL
DELISTED
CyberArk
CYBR
| $10.5M | 0.01% |
25,700
+15,100
| +142% | +$5.5M |
|
867
CALL
Prologis
PLD
$134B
| $10.4M | 0.01% |
99,400
-12,100
| -11% | -$1.27M |
|
868
CALL
Atlassian
TEAM
$20.7B
| $10.4M | 0.01% |
51,400
-35,200
| -41% | -$7.33M |
|
869
PUT
Peloton Interactive
PTON
$2.62B
| $10.4M | 0.01% |
1,497,600
+406,600
| +37% | +$2.64M |
|
870
CALL
Southern Copper
SCCO
$144B
| $10.4M | 0.01% |
106,563
+13,510
| +15% | +$1.19M |
|
871
PUT
Duolingo
DUOL
$5.53B
| $10.4M | 0.01% |
25,300
+13,900
| +122% | +$6.1M |
|
872
PUT
Centrus Energy
LEU
$3.31B
| $10.4M | 0.01% |
56,600
+2,500
| +5% | +$267K |
|
873
PUT
Trip.com Group
TCOM
$27B
| $10.4M | 0.01% |
176,800
-68,600
| -28% | -$4.12M |
|
874
CALL
Carlyle Group
CG
$16B
| $10.4M | 0.01% |
201,600
+113,800
| +130% | +$4.9M |
|
875
PUT
Comstock Resources
CRK
$4.09B
| $10.3M | 0.01% |
373,900
+245,300
| +191% | +$5.58M |
|
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.