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 | |
|---|---|---|---|---|---|---|
3426
MGIC Investment
MTG
$6.34B
| $541K | ﹤0.01% |
+19,450
| New | +$500K |
|
3427
CALL
Cabaletta Bio
CABA
$444M
| $540K | ﹤0.01% |
355,700
+305,700
| +611% | +$477K |
|
3428
Cars.com
CARS
$660M
| $540K | ﹤0.01% |
45,576
+28,511
| +167% | +$314K |
|
3429
Invesco CurrencyShares Euro Currency Trust
FXE
$341M
| $540K | ﹤0.01% |
4,964
-5,465
| -52% | -$572K |
|
|
BRSL
3430
Brightstar Lottery PLC
BRSL
$1.93B
| $540K | ﹤0.01% |
34,204
-10,894
| -24% | -$171K |
|
|
MREO
3431
CALL
Mereo BioPharma
MREO
$48.2M
| $539K | ﹤0.01% |
199,200
+142,300
| +250% | +$343K |
|
3432
PUT
RingCentral
RNG
$4.5B
| $538K | ﹤0.01% |
19,000
-14,000
| -42% | -$361K |
|
3433
Taylor Morrison
TMHC
| $538K | ﹤0.01% |
+8,765
| New | +$509K |
|
3434
AutoNation
AN
$7.1B
| $536K | ﹤0.01% |
+2,700
| New | +$487K |
|
3435
PUT
HDFC Bank
HDB
$119B
| $536K | ﹤0.01% |
14,000
-18,000
| -56% | -$652K |
|
3436
PUT
abrdn Physical Silver Shares ETF
SIVR
$4.06B
| $536K | ﹤0.01% |
15,600
+5,500
| +54% | +$176K |
|
3437
CALL
Vishay Precision Group
VPG
$1.36B
| $536K | ﹤0.01% |
+19,100
| New | +$470K |
|
|
TBCH
3438
Turtle Beach Corp
TBCH
$245M
| $536K | ﹤0.01% |
38,793
-3,975
| -9% | -$47.4K |
|
3439
CALL
Atomera
ATOM
$203M
| $535K | ﹤0.01% |
106,300
+31,600
| +42% | +$169K |
|
|
MFA
3440
PUT
MFA Financial
MFA
$927M
| $535K | ﹤0.01% |
56,600
+46,300
| +450% | +$437K |
|
3441
CALL
Arqit Quantum
ARQQ
$316M
| $533K | ﹤0.01% |
14,400
-15,800
| -52% | -$339K |
|
3442
PUT
Neogen
NEOG
$2.03B
| $533K | ﹤0.01% |
111,700
+72,400
| +184% | +$416K |
|
3443
PUT
Tyler Technologies
TYL
$13B
| $533K | ﹤0.01% |
900
-300
| -25% | -$170K |
|
3444
Green Dot
GDOT
$746M
| $532K | ﹤0.01% |
49,405
+41,032
| +490% | +$371K |
|
3445
CALL
Xenon Pharmaceuticals
XENE
$6.36B
| $532K | ﹤0.01% |
17,000
+15,400
| +963% | +$502K |
|
|
BULL
3446
Webull Corp
BULL
$4.01B
| $532K | ﹤0.01% |
+44,488
| New | +$689K |
|
3447
PUT
PACS Group
PACS
$7.45B
| $531K | ﹤0.01% |
41,100
+14,900
| +57% | +$155K |
|
|
SMST
3448
CALL
Defiance Daily Target 2x Short MSTR ETF
SMST
$27.6M
| $531K | ﹤0.01% |
+22,200
| New | +$806K |
|
3449
CALL
Sterling Infrastructure
STRL
$19.5B
| $530K | ﹤0.01% |
2,300
-22,600
| -91% | -$3.95M |
|
|
SAGE
3450
CALL
DELISTED
Sage Therapeutics
SAGE
| $528K | ﹤0.01% |
57,900
-6,700
| -10% | -$49.3K |
|
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.