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 | |
|---|---|---|---|---|---|---|
5401
CALL
Korea Electric Power
KEP
$15.3B
| $66K | ﹤0.01% |
4,000
-5,200
| -57% | -$82.3K |
|
5402
PUT
Commerce Bancshares
CBSH
$8.53B
| $65.7K | ﹤0.01% |
1,255
+415
| +49% | +$21.7K |
|
5403
CALL
Fidus Investment
FDUS
$749M
| $65.6K | ﹤0.01% |
3,400
+100
| +3% | +$1.99K |
|
5404
PUT
Mohawk Industries
MHK
$7.5B
| $65.6K | ﹤0.01% |
600
-4,500
| -88% | -$517K |
|
5405
CALL
KRONOS Worldwide
KRO
$693M
| $65.4K | ﹤0.01% |
+14,800
| New | +$71.9K |
|
5406
CALL
St. Joe Company
JOE
$3.54B
| $65.3K | ﹤0.01% |
1,100
-700
| -39% | -$39.2K |
|
|
5407
PUT
St. Joe Company
JOE
$3.54B
| $65.3K | ﹤0.01% |
1,100
+200
| +22% | +$11.2K |
|
5408
CALL
Odyssey Marine Exploration
OMEX
$34.9M
| $65.1K | ﹤0.01% |
33,200
-109,300
| -77% | -$253K |
|
5409
Acadia Pharmaceuticals
ACAD
$4.43B
| $65K | ﹤0.01% |
+2,435
| New | +$58.2K |
|
5410
Qualys
QLYS
$5.1B
| $65K | ﹤0.01% |
489
+422
| +630% | +$58.1K |
|
5411
PUT
Travere Therapeutics
TVTX
$5.2B
| $65K | ﹤0.01% |
1,700
-59,100
| -97% | -$1.92M |
|
5412
PUT
Dorchester Minerals
DMLP
$1.33B
| $64.8K | ﹤0.01% |
2,900
+1,900
| +190% | +$44.4K |
|
5413
CALL
Karyopharm Therapeutics
KPTI
$43.5M
| $64.8K | ﹤0.01% |
8,800
-17,800
| -67% | -$109K |
|
5414
Federal Agricultural Mortgage
AGM
$2.47B
| $64.6K | ﹤0.01% |
368
-120
| -25% | -$20.2K |
|
5415
CALL
GFL Environmental
GFL
$14.9B
| $64.4K | ﹤0.01% |
1,500
-15,200
| -91% | -$679K |
|
|
LX
5416
PUT
LexinFintech Holdings
LX
$241M
| $64.4K | ﹤0.01% |
19,700
-11,700
| -37% | -$48K |
|
|
HUSE
5417
CALL
DELISTED
Strategy Shares US Market Rotation Strategy ETF
HUSE
| $64.3K | ﹤0.01% |
2,100
+500
| +31% | +$15.3K |
|
5418
PUT
Arcus Biosciences
RCUS
$3.55B
| $64.3K | ﹤0.01% |
2,700
-200
| -7% | -$4.08K |
|
5419
CALL
Fresenius Medical Care
FMS
$13.8B
| $64.3K | ﹤0.01% |
2,700
-5,700
| -68% | -$142K |
|
5420
CALL
Kodiak Sciences
KOD
$2.6B
| $64.3K | ﹤0.01% |
2,300
-1,200
| -34% | -$24.6K |
|
5421
PUT
C.H. Robinson
CHRW
$17.4B
| $64.3K | ﹤0.01% |
400
-1,800
| -82% | -$266K |
|
5422
Limoneira
LMNR
$235M
| $64.1K | ﹤0.01% |
5,081
+4,951
| +3,808% | +$69.9K |
|
5423
American Battery Technology Co
ABAT
$285M
| $64.1K | ﹤0.01% |
19,203
-96,471
| -83% | -$452K |
|
5424
PUT
Hyatt Hotels
H
$16.4B
| $64.1K | ﹤0.01% |
400
-600
| -60% | -$91.9K |
|
|
HOOG
5425
Leverage Shares 2X Long HOOD Daily ETF
HOOG
$49.6M
| $64.1K | ﹤0.01% |
1,180
+1,004
| +570% | +$88.8K |
|
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.