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 | |
|---|---|---|---|---|---|---|
4251
Ocular Therapeutix
OCUL
$1.83B
| $197K | ﹤0.01% |
16,202
-1,258
| -7% | -$15.3K |
|
4252
PUT
Alto Ingredients
ALTO
$338M
| $196K | ﹤0.01% |
68,100
+34,800
| +105% | +$65.6K |
|
|
DPRO
4253
Draganfly
DPRO
$140M
| $196K | ﹤0.01% |
+28,357
| New | +$239K |
|
4254
CALL
Rocket Pharmaceuticals
RCKT
$343M
| $196K | ﹤0.01% |
55,800
-188,000
| -77% | -$644K |
|
|
FLNA
4255
CALL
Filana Therapeutics
FLNA
$42M
| $196K | ﹤0.01% |
102,500
-39,300
| -28% | -$126K |
|
|
MRX
4256
CALL
Marex Group Limited Ordinary Shares
MRX
$4.54B
| $196K | ﹤0.01% |
5,100
-20,000
| -80% | -$680K |
|
4257
Iron Mountain
IRM
$35.9B
| $196K | ﹤0.01% |
+2,357
| New | +$221K |
|
4258
CALL
Outlook Therapeutics
OTLK
$187M
| $195K | ﹤0.01% |
123,600
+108,300
| +708% | +$173K |
|
4259
CALL
Health Catalyst
HCAT
$160M
| $195K | ﹤0.01% |
81,700
+2,100
| +3% | +$5.74K |
|
|
GPGI
4260
CALL
GPGI Inc
GPGI
$3.87B
| $195K | ﹤0.01% |
10,100
+3,700
| +58% | +$73.8K |
|
4261
CALL
Pebblebrook Hotel Trust
PEB
$2.18B
| $195K | ﹤0.01% |
+17,200
| New | +$189K |
|
4262
Nokia
NOK
$46.9B
| $194K | ﹤0.01% |
30,054
-99,307
| -77% | -$616K |
|
4263
iShares Micro-Cap ETF
IWC
$1.42B
| $194K | ﹤0.01% |
1,233
+1,059
| +609% | +$165K |
|
|
GOOS
4264
PUT
Canada Goose Holdings
GOOS
$903M
| $194K | ﹤0.01% |
15,000
-5,000
| -25% | -$66.5K |
|
4265
PUT
Corvus Pharmaceuticals
CRVS
$1.1B
| $194K | ﹤0.01% |
25,200
-5,000
| -17% | -$39.4K |
|
4266
PUT
Fidelity Enhanced Large Cap Core ETF
FELC
$7.78B
| $194K | ﹤0.01% |
3,400
-2,600
| -43% | -$98K |
|
4267
Phreesia
PHR
$689M
| $194K | ﹤0.01% |
11,448
+5,491
| +92% | +$113K |
|
4268
CALL
Cullinan Oncology
CGEM
$1.06B
| $194K | ﹤0.01% |
18,700
+13,500
| +260% | +$122K |
|
|
CSR
4269
CALL
Centerspace
CSR
$952M
| $193K | ﹤0.01% |
2,900
+400
| +16% | +$25.1K |
|
|
CYPH
4270
CALL
Cypherpunk Technologies Inc
CYPH
$64M
| $193K | ﹤0.01% |
166,700
+140,400
| +534% | +$153K |
|
4271
CALL
Exagen
XGN
$105M
| $193K | ﹤0.01% |
31,800
+10,000
| +46% | +$91K |
|
4272
PUT
LKQ Corp
LKQ
$6.72B
| $193K | ﹤0.01% |
6,400
+1,800
| +39% | +$54.3K |
|
4273
CALL
Main Street Capital
MAIN
$5.05B
| $193K | ﹤0.01% |
3,200
-8,900
| -74% | -$525K |
|
4274
CALL
iShares Core Dividend ETF
DIVB
$1.71B
| $193K | ﹤0.01% |
4,300
+800
| +23% | +$42K |
|
4275
California Resources
CRC
$4.49B
| $193K | ﹤0.01% |
4,314
-2,031
| -32% | -$96.4K |
|
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.