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 | |
|---|---|---|---|---|---|---|
6226
CALL
Clearfield
CLFD
$411M
| $26.2K | ﹤0.01% |
900
+100
| +13% | +$3.21K |
|
|
DOO
6227
Bombardier Recreational Products
DOO
$4.54B
| $26.2K | ﹤0.01% |
370
-272
| -42% | -$18.5K |
|
6228
PUT
Kilroy Realty
KRC
$4.52B
| $26.2K | ﹤0.01% |
+700
| New | +$28.6K |
|
6229
PUT
Textron
TXT
$14.7B
| $26.2K | ﹤0.01% |
300
-5,900
| -95% | -$494K |
|
|
WW
6230
PUT
WW International
WW
$144M
| $26.1K | ﹤0.01% |
15,500
-10,500
| -40% | -$293K |
|
6231
CALL
Ampco-Pittsburgh
AP
$163M
| $26.1K | ﹤0.01% |
+4,900
| New | +$13.6K |
|
|
CVGW
6232
CALL
DELISTED
Calavo Growers
CVGW
| $26.1K | ﹤0.01% |
1,200
-200
| -14% | -$4.43K |
|
6233
PUT
HighPeak Energy
HPK
$903M
| $26.1K | ﹤0.01% |
5,500
-1,400
| -20% | -$8.41K |
|
6234
CALL
PepGen
PEPG
$122M
| $26K | ﹤0.01% |
4,000
-9,300
| -70% | -$48.3K |
|
6235
Cambria Tail Risk ETF
TAIL
$147M
| $26K | ﹤0.01% |
2,265
+2,229
| +6,192% | +$26.4K |
|
6236
Weatherford International
WFRD
$6.29B
| $26K | ﹤0.01% |
+332
| New | +$24.1K |
|
6237
Fidelity MSCI Industrials Index ETF
FIDU
$2.3B
| $26K | ﹤0.01% |
315
-123
| -28% | -$10.1K |
|
6238
CALL
Brookdale Senior Living
BKD
$3.49B
| $25.9K | ﹤0.01% |
2,400
-11,100
| -82% | -$109K |
|
6239
CALL
Adeia
ADEA
$2.94B
| $25.9K | ﹤0.01% |
1,500
-20,400
| -93% | -$303K |
|
6240
AGF US Market Neutral Anti-Beta Fund
BTAL
$304M
| $25.9K | ﹤0.01% |
1,798
-2,776
| -61% | -$41.8K |
|
|
IMMP
6241
Immutep
IMMP
$56.3M
| $25.8K | ﹤0.01% |
9,037
+5,941
| +192% | +$12.5K |
|
6242
Aramark
ARMK
$15B
| $25.8K | ﹤0.01% |
+701
| New | +$26.7K |
|
|
ACRE
6243
PUT
Ares Commercial Real Estate
ACRE
$236M
| $25.8K | ﹤0.01% |
5,400
+200
| +4% | +$972 |
|
6244
PUT
DTE Energy
DTE
$29.5B
| $25.8K | ﹤0.01% |
200
-700
| -78% | -$95.1K |
|
6245
Amplify CWP Enhanced Dividend Income ETF
DIVO
$7.5B
| $25.8K | ﹤0.01% |
+579
| New | +$26.1K |
|
6246
BuzzFeed
BZFD
$99M
| $25.7K | ﹤0.01% |
27,613
-107,741
| -80% | -$136K |
|
6247
CPS Technologies
CPSH
$75.5M
| $25.7K | ﹤0.01% |
8,304
-2,329
| -22% | -$8.24K |
|
|
VIVO
6248
CALL
VivoPower PLC
VIVO
$110M
| $25.6K | ﹤0.01% |
11,300
-29,700
| -72% | -$102K |
|
|
ARX
6249
Accelerant Holdings
ARX
$2.59B
| $25.6K | ﹤0.01% |
+1,564
| New | +$22K |
|
6250
PUT
Titan Machinery
TITN
$396M
| $25.6K | ﹤0.01% |
1,700
-6,700
| -80% | -$108K |
|
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.