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 | |
|---|---|---|---|---|---|---|
2251
CALL
EXL Service
EXLS
$4.23B
| $1.71M | ﹤0.01% |
39,000
+16,700
| +75% | +$763K |
|
2252
PUT
Praxis Precision Medicines
PRAX
$9.07B
| $1.71M | ﹤0.01% |
40,600
-5,500
| -12% | -$209K |
|
|
2253
Netflix
NFLX
$292B
| $1.7M | ﹤0.01% |
12,730
-338,710
| -96% | -$38.3M |
|
2254
CALL
Enpro
NPO
$7.05B
| $1.7M | ﹤0.01% |
8,900
+8,300
| +1,383% | +$1.42M |
|
2255
PUT
Remitly
RELY
$4.74B
| $1.7M | ﹤0.01% |
90,500
+24,600
| +37% | +$512K |
|
2256
CALL
Redwire
RDW
$2.08B
| $1.7M | ﹤0.01% |
104,100
-1,500
| -1% | -$19.5K |
|
2257
CALL
Guidewire Software
GWRE
$11.5B
| $1.7M | ﹤0.01% |
7,200
-2,700
| -27% | -$580K |
|
2258
PUT
Warrior Met Coal
HCC
$4.23B
| $1.69M | ﹤0.01% |
36,900
-100
| -0.3% | -$4.64K |
|
|
GRMN
2259
CALL
Garmin
GRMN
$46.9B
| $1.69M | ﹤0.01% |
8,100
-15,100
| -65% | -$3M |
|
2260
CALL
Knight Transportation
KNX
$11.8B
| $1.69M | ﹤0.01% |
38,200
-250,300
| -87% | -$10.6M |
|
2261
PUT
Ollie's Bargain Outlet
OLLI
$4.01B
| $1.69M | ﹤0.01% |
12,800
-31,800
| -71% | -$3.64M |
|
2262
CALL
Bruker
BRKR
$9.2B
| $1.69M | ﹤0.01% |
40,900
+37,100
| +976% | +$1.43M |
|
2263
CALL
Westlake Corp
WLK
$9.46B
| $1.69M | ﹤0.01% |
22,200
+20,700
| +1,380% | +$1.69M |
|
2264
PUT
Amkor Technology
AMKR
$16.1B
| $1.68M | ﹤0.01% |
80,100
-3,900
| -5% | -$72K |
|
2265
CALL
Silicon Laboratories
SLAB
$7.15B
| $1.68M | ﹤0.01% |
11,400
+11,300
| +11,300% | +$1.34M |
|
|
ONT
2266
CALL
Onterris Inc
ONT
$710M
| $1.68M | ﹤0.01% |
76,700
+5,400
| +8% | +$96.8K |
|
2267
iShares 7-10 Year Treasury Bond ETF
IEF
$47.1B
| $1.68M | ﹤0.01% |
+17,500
| New | +$1.65M |
|
2268
PUT
Transocean
RIG
$5.92B
| $1.67M | ﹤0.01% |
645,700
-4,900
| -0.8% | -$12.6K |
|
2269
CALL
Arvinas
ARVN
$518M
| $1.67M | ﹤0.01% |
227,100
-273,100
| -55% | -$2.01M |
|
2270
CALL
Aurora
AUR
$11.7B
| $1.67M | ﹤0.01% |
319,000
-196,400
| -38% | -$1.23M |
|
2271
CALL
Keysight
KEYS
$54.5B
| $1.67M | ﹤0.01% |
10,200
-29,300
| -74% | -$4.47M |
|
2272
PUT
Eldorado Gold
EGO
$8.31B
| $1.67M | ﹤0.01% |
81,900
+1,600
| +2% | +$31.1K |
|
2273
PUT
Fluence Energy
FLNC
$1.78B
| $1.66M | ﹤0.01% |
247,900
-13,700
| -5% | -$65.3K |
|
2274
CALL
Grindr
GRND
$2.64B
| $1.66M | ﹤0.01% |
73,200
+10,500
| +17% | +$231K |
|
|
WAY
2275
CALL
Waystar Holding Corp
WAY
$4.32B
| $1.66M | ﹤0.01% |
40,600
-400
| -1% | -$15.4K |
|
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.