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 |
Netflix
NFLX
|
+$73.1M |
| 2 |
Western Digital
WDC
|
+$51.8M |
| 3 |
iShares Semiconductor ETF
SOXX
|
+$46M |
| 4 |
Meta Platforms (Facebook)
META
|
+$41.8M |
| 5 |
Alibaba
BABA
|
+$37.1M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
NVIDIA
NVDA
|
+$262M |
| 2 |
Microsoft
MSFT
|
+$194M |
| 3 |
iShares Russell 2000 ETF
IWM
|
+$149M |
| 4 |
Apple
AAPL
|
+$119M |
| 5 |
Amazon
AMZN
|
+$107M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 0.59% |
| 2 | Consumer Discretionary | 0.21% |
| 3 | Healthcare | 0.2% |
| 4 | Industrials | 0.18% |
| 5 | Communication Services | 0.16% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
2226
CALL
MoonLake Immunotherapeutics
MLTX
$1.59B
| $1.5M | ﹤0.01% |
114,000
-88,500
| -44% | -$1.04M |
|
2227
PUT
RadNet
RDNT
$4.84B
| $1.49M | ﹤0.01% |
20,900
+20,700
| +10,350% | +$1.6M |
|
2228
PUT
TMC The Metals Company
TMC
$1.59B
| $1.49M | ﹤0.01% |
241,400
-371,900
| -61% | -$2.61M |
|
2229
CALL
Core & Main
CNM
$8.17B
| $1.49M | ﹤0.01% |
28,600
-75,200
| -72% | -$3.86M |
|
2230
Molina Healthcare
MOH
$10.3B
| $1.48M | ﹤0.01% |
+8,557
| New | +$1.41M |
|
2231
CALL
DuPont de Nemours
DD
$18.6B
| $1.48M | ﹤0.01% |
52,833
-123,708
| -70% | -$13.9M |
|
2232
Veeva Systems
VEEV
$30.3B
| $1.47M | ﹤0.01% |
+6,604
| New | +$1.75M |
|
2233
Direxion Daily AAPL Bull 2X ETF
AAPU
$193M
| $1.47M | ﹤0.01% |
43,884
-47,867
| -52% | -$1.67M |
|
2234
CALL
Zevra Therapeutics
ZVRA
$563M
| $1.47M | ﹤0.01% |
164,400
-15,500
| -9% | -$147K |
|
2235
CALL
ReNew
RNW
$2.24B
| $1.47M | ﹤0.01% |
260,700
+256,000
| +5,447% | +$1.85M |
|
2236
PUT
Canadian National Railway
CNI
$78.3B
| $1.47M | ﹤0.01% |
14,900
+1,600
| +12% | +$154K |
|
2237
CALL
Braze
BRZE
$2.45B
| $1.47M | ﹤0.01% |
42,900
+8,400
| +24% | +$249K |
|
2238
CALL
Vipshop
VIPS
$6.84B
| $1.47M | ﹤0.01% |
83,000
+49,500
| +148% | +$952K |
|
2239
PUT
Banco Bradesco
BBD
$38.1B
| $1.46M | ﹤0.01% |
439,500
+45,000
| +11% | +$153K |
|
|
FETH
2240
CALL
Fidelity Ethereum Fund
FETH
$1B
| $1.46M | ﹤0.01% |
49,400
-15,000
| -23% | -$518K |
|
|
SEI
2241
PUT
Solaris Energy Infrastructure
SEI
$3.31B
| $1.46M | ﹤0.01% |
31,800
-180,200
| -85% | -$8.72M |
|
|
GRMN
2242
CALL
Garmin
GRMN
$46.9B
| $1.46M | ﹤0.01% |
7,200
-3,000
| -29% | -$652K |
|
2243
iShares Core S&P US Growth ETF
IUSG
$31.1B
| $1.46M | ﹤0.01% |
+8,695
| New | +$1.45M |
|
2244
CALL
Coursera
COUR
$1.54B
| $1.46M | ﹤0.01% |
198,400
-56,300
| -22% | -$490K |
|
|
DFTX
2245
PUT
Definium Therapeutics
DFTX
$5.73B
| $1.46M | ﹤0.01% |
109,000
+10,200
| +10% | +$126K |
|
2246
Harmony Gold Mining
HMY
$9.92B
| $1.45M | ﹤0.01% |
72,800
-5,033
| -6% | -$93.9K |
|
2247
CALL
ResMed
RMD
$28.3B
| $1.45M | ﹤0.01% |
6,000
-9,300
| -61% | -$2.38M |
|
2248
Invesco
IVZ
$13.3B
| $1.44M | ﹤0.01% |
55,004
+48,796
| +786% | +$1.19M |
|
2249
CALL
State Street
STT
$50.9B
| $1.44M | ﹤0.01% |
11,200
-34,900
| -76% | -$4.18M |
|
2250
Lamb Weston
LW
$6.82B
| $1.44M | ﹤0.01% |
34,455
+23,707
| +221% | +$1.4M |
|
Similar funds
Simplex Trading's Q4 2025 Portfolio in Review
As of Q4 2025, Simplex Trading held 10,526 positions worth $177B, down 9% from $195B the previous quarter. Its ten largest holdings account for 49% of the portfolio.
Simplex Trading withdrew a net $23.2B in Q4 2025, closing 2,184 positions and reducing 4,088 holdings. Its most notable exit was iShares Russell 2000 ETF, an estimated $149M position sold in full.
By sector, the portfolio is most concentrated in Technology at 0.59% of assets, down from 0.79% a quarter earlier, followed by Consumer Discretionary and Healthcare.
Against the trend, Simplex Trading opened a new position in Western Digital worth $58.9M.
- Simplex Trading's largest Q4 2025 buy was Western Digital: 341,762 shares worth $58.9M.
- Simplex Trading added most to Netflix in Q4 2025, an estimated $73.1M increase.
- Simplex Trading's biggest Q4 2025 reduction was NVIDIA, cutting an estimated $262M.
- Simplex Trading fully exited iShares Russell 2000 ETF in Q4 2025, selling an estimated $149M.
- Simplex Trading's ten largest holdings make up 49% of its $177B portfolio in Q4 2025.
- Simplex Trading opened 1,476 new positions and closed 2,184 in Q4 2025.
- Simplex Trading's portfolio value fell 9% quarter-over-quarter to $177B.
Based on Simplex Trading's 13F filing for Q4 2025, filed 11 Feb 2026.