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 | |
|---|---|---|---|---|---|---|
|
LTM
6201
PUT
LATAM Airlines Group S.A.
LTM
$15.1B
| $27K | ﹤0.01% |
500
-300
| -38% | -$14.2K |
|
6202
Dream Finders Homes
DFH
$1.16B
| $27K | ﹤0.01% |
1,578
+124
| +9% | +$2.54K |
|
|
ABVX
6203
PUT
Abivax
ABVX
$10.9B
| $27K | ﹤0.01% |
+200
| New | +$21.8K |
|
6204
CALL
Palomar
PLMR
$3.55B
| $27K | ﹤0.01% |
200
-300
| -60% | -$36.6K |
|
6205
Marcus Corp
MCS
$897M
| $26.9K | ﹤0.01% |
1,735
-30
| -2% | -$446 |
|
6206
CALL
Verra Mobility
VRRM
$804M
| $26.9K | ﹤0.01% |
1,200
+700
| +140% | +$16K |
|
6207
Vanguard Morningstar Small-Cap Growth ETF
VBK
$23.1B
| $26.9K | ﹤0.01% |
+89
| New | +$26.9K |
|
6208
PUT
Adient
ADNT
$1.65B
| $26.8K | ﹤0.01% |
1,400
-7,200
| -84% | -$151K |
|
6209
PUT
Tetra Tech
TTEK
$8.49B
| $26.8K | ﹤0.01% |
800
-116,200
| -99% | -$3.93M |
|
6210
AdvisorShares Ranger Equity Bear ETF
HDGE
$60M
| $26.8K | ﹤0.01% |
1,674
-1,609
| -49% | -$26.8K |
|
6211
Viper Energy
VNOM
$8.71B
| $26.8K | ﹤0.01% |
+694
| New | +$26.3K |
|
|
SFD
6212
PUT
Smithfield Foods
SFD
$10.2B
| $26.8K | ﹤0.01% |
1,200
-1,000
| -45% | -$22K |
|
6213
Landstar System
LSTR
$5.93B
| $26.7K | ﹤0.01% |
+186
| New | +$24.8K |
|
6214
PUT
POSCO
PKX
$16.1B
| $26.6K | ﹤0.01% |
500
-5,100
| -91% | -$269K |
|
6215
CALL
Evolus
EOLS
$385M
| $26.6K | ﹤0.01% |
4,000
+2,700
| +208% | +$18.3K |
|
6216
PUT
Qualys
QLYS
$5.1B
| $26.6K | ﹤0.01% |
200
+100
| +100% | +$13.8K |
|
6217
Phathom Pharmaceuticals
PHAT
$708M
| $26.5K | ﹤0.01% |
1,599
-18,361
| -92% | -$262K |
|
6218
Schwab Short-Term US Treasury ETF
SCHO
$12.8B
| $26.4K | ﹤0.01% |
1,083
+1,063
| +5,315% | +$25.9K |
|
|
WSR
6219
CALL
DELISTED
Whitestone REIT
WSR
| $26.4K | ﹤0.01% |
1,900
-1,900
| -50% | -$24.5K |
|
6220
Fidelity MSCI Communication Services Index ETF
FCOM
$1.77B
| $26.4K | ﹤0.01% |
360
+161
| +81% | +$11.4K |
|
6221
CALL
Thomson Reuters
TRI
$42.8B
| $26.4K | ﹤0.01% |
197
-98
| -33% | -$14.2K |
|
|
OLP
6222
PUT
One Liberty Properties
OLP
$530M
| $26.4K | ﹤0.01% |
1,300
+800
| +160% | +$16.5K |
|
6223
PUT
Rekor Systems
REKR
$85.8M
| $26.4K | ﹤0.01% |
19,100
-19,500
| -51% | -$39.8K |
|
6224
CALL
Descartes Systems
DSGX
$6.44B
| $26.3K | ﹤0.01% |
300
-900
| -75% | -$80.4K |
|
6225
PUT
Arqit Quantum
ARQQ
$298M
| $26.3K | ﹤0.01% |
1,200
-10,700
| -90% | -$370K |
|
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.