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 | |
|---|---|---|---|---|---|---|
|
ALEX
5701
CALL
DELISTED
Alexander & Baldwin
ALEX
| $47.5K | ﹤0.01% |
2,300
+2,100
| +1,050% | +$36.5K |
|
5702
PUT
Delek US
DK
$4.16B
| $47.5K | ﹤0.01% |
1,600
-12,500
| -89% | -$446K |
|
5703
Paylocity
PCTY
$7.38B
| $47.4K | ﹤0.01% |
+311
| New | +$46.3K |
|
5704
PUT
Onto Innovation
ONTO
$12.9B
| $47.4K | ﹤0.01% |
300
-3,200
| -91% | -$454K |
|
5705
Gran Tierra Energy
GTE
$265M
| $47.3K | ﹤0.01% |
11,163
+6,147
| +123% | +$25.9K |
|
|
COYY
5706
GraniteShares YieldBOOST COIN ETF
COYY
$18.7M
| $47.3K | ﹤0.01% |
+1,005
| New | +$73.1K |
|
5707
iShares MSCI USA Min Vol Factor ETF
USMV
$23.5B
| $47.3K | ﹤0.01% |
502
-2,461
| -83% | -$232K |
|
5708
PUT
GFL Environmental
GFL
$14.9B
| $47.2K | ﹤0.01% |
1,100
-55,800
| -98% | -$2.49M |
|
5709
Senseonics Holdings Inc
SENS
$263M
| $47.2K | ﹤0.01% |
8,558
+5,459
| +176% | +$38K |
|
5710
CALL
BGSF Inc
BGSF
$59.5M
| $47.2K | ﹤0.01% |
10,200
-3,900
| -28% | -$15.9K |
|
5711
Telos
TLS
$332M
| $47K | ﹤0.01% |
9,221
-24,699
| -73% | -$154K |
|
5712
CALL
Trimble
TRMB
$13.2B
| $47K | ﹤0.01% |
600
-2,900
| -83% | -$231K |
|
5713
MarketAxess Holdings
MKTX
$5.71B
| $46.9K | ﹤0.01% |
259
-2,030
| -89% | -$346K |
|
5714
iShares MSCI Taiwan ETF
EWT
$9.86B
| $46.9K | ﹤0.01% |
738
-637
| -46% | -$41K |
|
5715
PUT
CubeSmart
CUBE
$9.39B
| $46.9K | ﹤0.01% |
1,300
+900
| +225% | +$34.2K |
|
5716
Moelis & Co
MC
$4.97B
| $46.7K | ﹤0.01% |
680
-128
| -16% | -$8.54K |
|
5717
PUT
Tanger
SKT
$4.67B
| $46.7K | ﹤0.01% |
1,400
+500
| +56% | +$16.7K |
|
5718
PUT
Universal Display
OLED
$3.68B
| $46.7K | ﹤0.01% |
400
-8,400
| -95% | -$1.09M |
|
|
YETH
5719
Roundhill Ether Covered Call Strategy ETF
YETH
$59.1M
| $46.6K | ﹤0.01% |
2,664
-1,525
| -36% | -$31.3K |
|
5720
Blue Bird Corp
BLBD
$2.35B
| $46.6K | ﹤0.01% |
992
-67
| -6% | -$3.5K |
|
5721
CALL
ABM Industries
ABM
$2.81B
| $46.5K | ﹤0.01% |
1,100
-300
| -21% | -$13.2K |
|
|
YALA
5722
PUT
Yalla Group
YALA
$818M
| $46.5K | ﹤0.01% |
6,700
+5,200
| +347% | +$37.2K |
|
5723
LXP Industrial Trust
LXP
$3.57B
| $46.4K | ﹤0.01% |
936
-37
| -4% | -$1.77K |
|
|
EFC
5724
Ellington Financial
EFC
$1.67B
| $46.4K | ﹤0.01% |
+3,415
| New | +$46.5K |
|
|
BAND
5725
PUT
Bandwidth Inc
BAND
$1.26B
| $46.4K | ﹤0.01% |
3,000
+2,400
| +400% | +$36.4K |
|
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.