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 | Miscellaneous | 98.27% |
| 2 | Technology | 0.59% |
| 3 | Consumer Discretionary | 0.21% |
| 4 | Healthcare | 0.2% |
| 5 | Industrials | 0.18% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
|
FIG
1176
PUT
Figma
FIG
$12.9B
| $5.77M | ﹤0.01% |
154,500
-131,600
| -46% | -$5.95M |
|
1177
PUT
Generac Holdings
GNRC
$11.1B
| $5.77M | ﹤0.01% |
42,300
-15,800
| -27% | -$2.55M |
|
1178
CALL
YPF Sociedad Anonima ADS
YPF
$20.6B
| $5.75M | ﹤0.01% |
158,900
-61,400
| -28% | -$2.04M |
|
|
VISN
1179
PUT
Vistance Networks Inc
VISN
$1.48B
| $5.75M | ﹤0.01% |
316,900
-44,400
| -12% | -$766K |
|
1180
Applied Digital
APLD
$7.5B
| $5.73M | ﹤0.01% |
233,669
-9,131
| -4% | -$263K |
|
1181
PUT
American Tower
AMT
$81.9B
| $5.72M | ﹤0.01% |
32,600
-21,800
| -40% | -$3.97M |
|
1182
iShares Biotechnology ETF
IBB
$10.7B
| $5.72M | ﹤0.01% |
+33,879
| New | +$5.5M |
|
1183
Celestica
CLS
$39.4B
| $5.72M | ﹤0.01% |
+19,342
| New | +$5.83M |
|
1184
PUT
Capri Holdings
CPRI
$1.54B
| $5.71M | ﹤0.01% |
234,000
-129,100
| -36% | -$2.99M |
|
1185
CALL
Cogent Communications
CCOI
$515M
| $5.7M | ﹤0.01% |
264,500
+244,800
| +1,243% | +$7.23M |
|
1186
CALL
MKS Inc
MKSI
$17.6B
| $5.69M | ﹤0.01% |
35,600
+14,400
| +68% | +$2.14M |
|
1187
Applied Optoelectronics
AAOI
$8.96B
| $5.68M | ﹤0.01% |
162,908
+39,163
| +32% | +$1.17M |
|
1188
PUT
Maplebear
CART
$11.8B
| $5.68M | ﹤0.01% |
126,200
+44,700
| +55% | +$1.83M |
|
1189
CALL
Cenovus Energy
CVE
$59.7B
| $5.67M | ﹤0.01% |
335,200
-532,100
| -61% | -$9.24M |
|
|
APLS
1190
CALL
DELISTED
Apellis Pharmaceuticals
APLS
| $5.67M | ﹤0.01% |
225,700
+76,600
| +51% | +$1.8M |
|
1191
Under Armour
UAA
$2.26B
| $5.67M | ﹤0.01% |
1,140,496
+410,009
| +56% | +$1.9M |
|
1192
CALL
Hertz
HTZ
$820M
| $5.66M | ﹤0.01% |
1,100,400
+211,400
| +24% | +$1.15M |
|
1193
PUT
Truist Financial
TFC
$63.1B
| $5.65M | ﹤0.01% |
114,900
-45,100
| -28% | -$2.08M |
|
1194
Quantum Computing Inc
QUBT
$1.81B
| $5.63M | ﹤0.01% |
+549,049
| New | +$7.81M |
|
1195
PUT
Coeur Mining
CDE
$21.8B
| $5.63M | ﹤0.01% |
315,700
+48,300
| +18% | +$840K |
|
1196
CALL
ATI
ATI
$28.7B
| $5.61M | ﹤0.01% |
48,900
+19,600
| +67% | +$1.91M |
|
1197
Ford
F
$58.3B
| $5.6M | ﹤0.01% |
427,201
-77,081
| -15% | -$994K |
|
1198
CALL
Equinox Gold
EQX
$15B
| $5.6M | ﹤0.01% |
399,100
-359,300
| -47% | -$4.53M |
|
1199
PUT
Scorpio Tankers
STNG
$4.12B
| $5.6M | ﹤0.01% |
110,200
+21,600
| +24% | +$1.23M |
|
1200
CALL
ChargePoint
CHPT
$267M
| $5.6M | ﹤0.01% |
842,900
-139,700
| -14% | -$1.32M |
|
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's Q4 2025 filing shows 1,476 new, 2,599 increased, 4,088 reduced and 2,184 closed positions. Its largest new stake was Western Digital: 341,762 shares worth $58.9M. The largest sale was NVIDIA, an estimated $262M.
By sector, the portfolio is most concentrated in Miscellaneous at 98% of assets, up from 98% a quarter earlier, followed by Technology and Consumer Discretionary.
- 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.