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 | |
|---|---|---|---|---|---|---|
1151
CALL
Motorola Solutions
MSI
$77.5B
| $5.98M | ﹤0.01% |
15,600
+7,200
| +86% | +$2.89M |
|
1152
CALL
Best Buy
BBY
$19B
| $5.97M | ﹤0.01% |
89,200
+6,000
| +7% | +$458K |
|
1153
PUT
Duolingo
DUOL
$7.23B
| $5.97M | ﹤0.01% |
34,000
-37,700
| -53% | -$8.88M |
|
1154
PUT
Advance Auto Parts
AAP
$2.67B
| $5.96M | ﹤0.01% |
151,700
-21,300
| -12% | -$1.07M |
|
1155
PUT
Lennar Class A
LEN
$20.1B
| $5.96M | ﹤0.01% |
92,300
-31,900
| -26% | -$3.85M |
|
1156
PUT
Fluor
FLR
$7.51B
| $5.94M | ﹤0.01% |
150,000
-167,800
| -53% | -$7.42M |
|
1157
Global X Silver Miners ETF NEW
SIL
$5.31B
| $5.93M | ﹤0.01% |
+71,050
| New | +$5.24M |
|
1158
PUT
Alnylam Pharmaceuticals
ALNY
$35.6B
| $5.92M | ﹤0.01% |
14,900
-11,700
| -44% | -$5.18M |
|
1159
PUT
HP
HPQ
$29.4B
| $5.92M | ﹤0.01% |
265,800
-185,500
| -41% | -$4.73M |
|
|
HUT
1160
Hut 8
HUT
$11.5B
| $5.92M | ﹤0.01% |
128,859
+87,427
| +211% | +$3.85M |
|
1161
CALL
Tower Semiconductor
TSEM
$25.1B
| $5.91M | ﹤0.01% |
50,300
-21,800
| -30% | -$2.1M |
|
1162
PUT
Suncor Energy
SU
$78.8B
| $5.9M | ﹤0.01% |
133,100
-29,500
| -18% | -$1.25M |
|
1163
CALL
Air Products & Chemicals
APD
$67.1B
| $5.9M | ﹤0.01% |
23,900
-48,300
| -67% | -$12.2M |
|
1164
iShares MSCI Emerging Markets ETF
EEM
$31.9B
| $5.9M | ﹤0.01% |
107,806
-58,529
| -35% | -$3.18M |
|
1165
CALL
iPath Series B S&P 500 VIX Short-Term Futures ETN
VXX
$128M
| $5.89M | ﹤0.01% |
221,600
-338,300
| -60% | -$11.1M |
|
1166
PUT
Crocs
CROX
$5.63B
| $5.88M | ﹤0.01% |
68,700
-85,300
| -55% | -$7.13M |
|
1167
PUT
Viasat
VSAT
$10.4B
| $5.87M | ﹤0.01% |
170,200
-43,600
| -20% | -$1.54M |
|
1168
CALL
Peloton Interactive
PTON
$2.37B
| $5.83M | ﹤0.01% |
946,900
-654,800
| -41% | -$4.61M |
|
1169
PUT
Manchester United
MANU
$3.6B
| $5.83M | ﹤0.01% |
365,900
+4,600
| +1% | +$74.3K |
|
1170
State Street SPDR S&P Bank ETF
KBE
$1.62B
| $5.81M | ﹤0.01% |
95,664
+70,294
| +277% | +$4.14M |
|
1171
PUT
Globalstar
GSAT
$10.7B
| $5.8M | ﹤0.01% |
95,100
-107,000
| -53% | -$5.91M |
|
1172
PUT
Ares Capital
ARCC
$14.4B
| $5.8M | ﹤0.01% |
286,900
+49,400
| +21% | +$996K |
|
1173
CALL
Harley-Davidson
HOG
$2.95B
| $5.79M | ﹤0.01% |
282,800
-19,900
| -7% | -$489K |
|
|
DOCU
1174
CALL
DocuSign
DOCU
$13.1B
| $5.78M | ﹤0.01% |
84,500
-24,000
| -22% | -$1.66M |
|
|
WRD
1175
CALL
WeRide Inc
WRD
$1.97B
| $5.78M | ﹤0.01% |
665,700
+392,500
| +144% | +$3.65M |
|
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.