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 | |
|---|---|---|---|---|---|---|
1226
CALL
Welltower
WELL
$170B
| $5.27M | ﹤0.01% |
28,400
+12,500
| +79% | +$2.33M |
|
1227
PUT
Starwood Property Trust
STWD
$5.95B
| $5.27M | ﹤0.01% |
292,500
-243,000
| -45% | -$4.47M |
|
1228
CALL
abrdn Physical Gold Shares ETF
SGOL
$7.41B
| $5.26M | ﹤0.01% |
128,000
+112,600
| +731% | +$4.46M |
|
1229
PUT
TE Connectivity
TEL
$60.4B
| $5.26M | ﹤0.01% |
23,100
+19,900
| +622% | +$4.6M |
|
1230
CALL
Ero Copper
ERO
$3.64B
| $5.23M | ﹤0.01% |
184,900
+141,600
| +327% | +$3.3M |
|
1231
CALL
Illumina
ILMN
$33B
| $5.2M | ﹤0.01% |
45,500
-11,200
| -20% | -$1.31M |
|
1232
PUT
Edison International
EIX
$21.8B
| $5.19M | ﹤0.01% |
86,400
-56,900
| -40% | -$3.27M |
|
1233
PUT
McCormick & Company Non-Voting
MKC
$14B
| $5.18M | ﹤0.01% |
76,100
-19,900
| -21% | -$1.32M |
|
1234
CALL
Toyota
TM
$233B
| $5.18M | ﹤0.01% |
24,200
+7,200
| +42% | +$1.46M |
|
1235
PUT
Grab
GRAB
$14B
| $5.17M | ﹤0.01% |
1,036,700
+195,900
| +23% | +$1.08M |
|
1236
CALL
Logitech
LOGI
$14.6B
| $5.17M | ﹤0.01% |
51,600
+14,800
| +40% | +$1.66M |
|
1237
CALL
BioMarin Pharmaceuticals
BMRN
$12.9B
| $5.17M | ﹤0.01% |
87,000
+27,700
| +47% | +$1.51M |
|
1238
CALL
Monolithic Power Systems
MPWR
$60.1B
| $5.17M | ﹤0.01% |
5,700
+2,300
| +68% | +$2.21M |
|
1239
CALL
Aehr Test Systems
AEHR
$2.81B
| $5.15M | ﹤0.01% |
255,100
-14,100
| -5% | -$341K |
|
1240
CALL
Exelon
EXC
$45B
| $5.14M | ﹤0.01% |
117,900
+42,900
| +57% | +$1.96M |
|
1241
CALL
FTAI Aviation
FTAI
$20.2B
| $5.14M | ﹤0.01% |
26,100
-200
| -0.8% | -$34.1K |
|
1242
Cipher Digital
CIFR
$7.36B
| $5.14M | ﹤0.01% |
347,931
+326,870
| +1,552% | +$5.77M |
|
1243
PUT
Edwards Lifesciences
EW
$51.8B
| $5.12M | ﹤0.01% |
60,100
-14,700
| -20% | -$1.21M |
|
1244
CALL
Crown Castle
CCI
$32.3B
| $5.12M | ﹤0.01% |
57,600
-22,500
| -28% | -$2.07M |
|
|
1245
PUT
Logitech
LOGI
$14.6B
| $5.11M | ﹤0.01% |
51,000
-5,700
| -10% | -$641K |
|
|
KEEL
1246
CALL
Keel Infrastructure Corp
KEEL
$2.14B
| $5.11M | ﹤0.01% |
2,173,600
-331,000
| -13% | -$1.13M |
|
1247
CALL
Carrier Global
CARR
$49.2B
| $5.1M | ﹤0.01% |
96,600
-31,500
| -25% | -$1.75M |
|
|
1248
PUT
abrdn Physical Gold Shares ETF
SGOL
$7.41B
| $5.08M | ﹤0.01% |
123,700
+118,400
| +2,234% | +$4.69M |
|
1249
CALL
Floor & Decor
FND
$5.35B
| $5.08M | ﹤0.01% |
83,400
+31,000
| +59% | +$2.01M |
|
|
1250
PUT
Monolithic Power Systems
MPWR
$60.1B
| $5.08M | ﹤0.01% |
5,600
-3,300
| -37% | -$3.18M |
|
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.