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 | |
|---|---|---|---|---|---|---|
7376
HUTCHMED
HCM
$1.96B
| $5.53K | ﹤0.01% |
415
-614
| -60% | -$8.97K |
|
7377
PUT
Eastern Bankshares
EBC
$5.27B
| $5.53K | ﹤0.01% |
300
-200
| -40% | -$3.66K |
|
|
SVC
7378
PUT
Service Properties Trust
SVC
$1.05B
| $5.52K | ﹤0.01% |
600
-3,080
| -84% | -$30.9K |
|
7379
Franklin Wireless
FKWL
$27.2M
| $5.51K | ﹤0.01% |
1,262
-1,189
| -49% | -$5.59K |
|
7380
Digi International
DGII
$2.47B
| $5.5K | ﹤0.01% |
+127
| New | +$5.09K |
|
|
PPSI
7381
Pioneer Power Solutions
PPSI
$30.8M
| $5.48K | ﹤0.01% |
1,158
-8,370
| -88% | -$35K |
|
7382
PUT
Akebia Therapeutics
AKBA
$338M
| $5.47K | ﹤0.01% |
3,400
-97,900
| -97% | -$205K |
|
7383
Castor Maritime
CTRM
$18.3M
| $5.47K | ﹤0.01% |
2,643
-10,828
| -80% | -$22.6K |
|
7384
Paymentus
PAY
$4.62B
| $5.46K | ﹤0.01% |
+173
| New | +$5.64K |
|
7385
CALL
V2X
VVX
$2.7B
| $5.46K | ﹤0.01% |
100
| – | – |
|
7386
PUT
Douglas Elliman
DOUG
$156M
| $5.45K | ﹤0.01% |
2,300
+200
| +10% | +$514 |
|
7387
CALL
Alpha Tau Medical
DRTS
$1.01B
| $5.45K | ﹤0.01% |
+1,100
| New | +$4.64K |
|
7388
PUT
Rimini Street
RMNI
$457M
| $5.43K | ﹤0.01% |
1,400
-49,100
| -97% | -$204K |
|
7389
PUT
Hanmi Financial
HAFC
$935M
| $5.41K | ﹤0.01% |
200
| – | – |
|
7390
CALL
Allient
ALNT
$1.34B
| $5.38K | ﹤0.01% |
100
-300
| -75% | -$15.7K |
|
7391
Manhattan Associates
MANH
$11.9B
| $5.37K | ﹤0.01% |
+31
| New | +$5.67K |
|
7392
Navient
NAVI
$819M
| $5.36K | ﹤0.01% |
412
-1,508
| -79% | -$18.8K |
|
|
BTGD
7393
STKd 100% Bitcoin & 100% Gold ETF
BTGD
$41M
| $5.36K | ﹤0.01% |
156
-1,285
| -89% | -$50.9K |
|
|
AIFU
7394
PUT
AIFU Inc
AIFU
$193M
| $5.34K | ﹤0.01% |
+100
| New | +$7.7K |
|
7395
CALL
Andersons Inc
ANDE
$2.39B
| $5.32K | ﹤0.01% |
+100
| New | +$4.89K |
|
7396
PUT
Nexa Resources
NEXA
$1.61B
| $5.31K | ﹤0.01% |
+600
| New | +$3.91K |
|
7397
PUT
Ardmore Shipping
ASC
$683M
| $5.29K | ﹤0.01% |
500
-400
| -44% | -$4.76K |
|
7398
PUT
Calix
CALX
$2.24B
| $5.29K | ﹤0.01% |
100
-1,600
| -94% | -$93.2K |
|
7399
PUT
Lexicon Pharmaceuticals
LXRX
$1.03B
| $5.29K | ﹤0.01% |
4,600
-32,400
| -88% | -$44.5K |
|
7400
CALL
First Bancorp
FNLC
$401M
| $5.29K | ﹤0.01% |
+200
| New | +$5.16K |
|
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.