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 | |
|---|---|---|---|---|---|---|
1251
CALL
Sweetgreen
SG
$719M
| $5.07M | ﹤0.01% |
749,700
+291,000
| +63% | +$2M |
|
1252
CALL
W.P. Carey
WPC
$17B
| $5.07M | ﹤0.01% |
79,000
+7,800
| +11% | +$519K |
|
1253
CALL
Rockwell Automation
ROK
$51.7B
| $5.06M | ﹤0.01% |
13,000
-2,900
| -18% | -$1.09M |
|
1254
CALL
iShares Core MSCI Emerging Markets ETF
IEMG
$150B
| $5.05M | ﹤0.01% |
65,600
+17,500
| +36% | +$1.17M |
|
1255
CALL
Alnylam Pharmaceuticals
ALNY
$36.4B
| $5.05M | ﹤0.01% |
12,700
-4,400
| -26% | -$1.95M |
|
1256
CALL
Groupon
GRPN
$995M
| $5.03M | ﹤0.01% |
285,900
+62,100
| +28% | +$1.17M |
|
|
RNAM
1257
PUT
DELISTED
Avidity Biosciences
RNAM
| $5.03M | ﹤0.01% |
69,800
+9,500
| +16% | +$614K |
|
1258
PUT
CF Industries
CF
$19.1B
| $5.03M | ﹤0.01% |
65,000
-45,200
| -41% | -$3.71M |
|
|
TEM
1259
PUT
Tempus AI
TEM
$7.93B
| $5.03M | ﹤0.01% |
85,100
-180,800
| -68% | -$14.1M |
|
1260
CALL
Restaurant Brands International
QSR
$25.3B
| $5.02M | ﹤0.01% |
73,600
+3,900
| +6% | +$269K |
|
1261
State Street Materials Select Sector SPDR ETF
XLB
$8.48B
| $5.02M | ﹤0.01% |
+110,658
| New | +$4.89M |
|
1262
Invesco CurrencyShares Euro Currency Trust
FXE
$331M
| $5.02M | ﹤0.01% |
46,247
+26,655
| +136% | +$2.86M |
|
1263
PUT
Digital Realty Trust
DLR
$75.4B
| $5.01M | ﹤0.01% |
32,400
-31,100
| -49% | -$5.11M |
|
|
GPGI
1264
GPGI Inc
GPGI
$4.12B
| $5.01M | ﹤0.01% |
259,688
-6,797
| -3% | -$136K |
|
1265
PUT
Toast
TOST
$16.9B
| $5M | ﹤0.01% |
140,700
-120,000
| -46% | -$4.33M |
|
1266
CALL
Redwire
RDW
$2.12B
| $4.99M | ﹤0.01% |
656,900
+425,900
| +184% | +$3.12M |
|
1267
PUT
Hertz
HTZ
$578M
| $4.99M | ﹤0.01% |
970,100
-682,900
| -41% | -$3.73M |
|
1268
PUT
WD-40
WDFC
$3.12B
| $4.96M | ﹤0.01% |
25,200
+25,100
| +25,100% | +$4.95M |
|
1269
CALL
Fluence Energy
FLNC
$1.83B
| $4.95M | ﹤0.01% |
250,500
-559,700
| -69% | -$10.5M |
|
1270
CALL
Mobileye
MBLY
$7.07B
| $4.95M | ﹤0.01% |
474,600
-139,100
| -23% | -$1.74M |
|
|
SLNO
1271
PUT
DELISTED
Soleno Therapeutics
SLNO
| $4.95M | ﹤0.01% |
107,000
+47,100
| +79% | +$2.58M |
|
1272
PUT
United States Natural Gas Fund
UNG
$470M
| $4.95M | ﹤0.01% |
406,200
-61,900
| -13% | -$833K |
|
1273
CALL
Nice
NICE
$5.27B
| $4.94M | ﹤0.01% |
43,700
+18,500
| +73% | +$2.23M |
|
|
BLSH
1274
CALL
Bullish
BLSH
$3.65B
| $4.93M | ﹤0.01% |
130,300
+12,200
| +10% | +$594K |
|
1275
CALL
United States Antimony
UAMY
$784M
| $4.93M | ﹤0.01% |
982,600
+673,000
| +217% | +$5.28M |
|
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.