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 | |
|---|---|---|---|---|---|---|
5651
MediaAlpha
MAX
$758M
| $50.2K | ﹤0.01% |
3,875
+1,108
| +40% | +$13.5K |
|
5652
Aclaris Therapeutics
ACRS
$726M
| $50.2K | ﹤0.01% |
+16,668
| New | +$42.1K |
|
5653
OptimizeRx
OPRX
$114M
| $50.2K | ﹤0.01% |
4,091
+3,397
| +489% | +$55.5K |
|
|
TBI
5654
Trueblue
TBI
$215M
| $50.1K | ﹤0.01% |
11,018
+3,995
| +57% | +$20.5K |
|
5655
PUT
Kulicke & Soffa
KLIC
$4.67B
| $50.1K | ﹤0.01% |
1,100
+100
| +10% | +$4.22K |
|
5656
CALL
Rentokil
RTO
$11.8B
| $50.1K | ﹤0.01% |
1,700
-9,600
| -85% | -$267K |
|
5657
PUT
1st Source
SRCE
$2.16B
| $50K | ﹤0.01% |
800
-200
| -20% | -$12.4K |
|
|
DHC
5658
CALL
Diversified Healthcare Trust
DHC
$2.15B
| $50K | ﹤0.01% |
10,300
+2,200
| +27% | +$9.98K |
|
5659
PUT
Extreme Networks
EXTR
$3.94B
| $50K | ﹤0.01% |
3,000
-500
| -14% | -$9.18K |
|
5660
PUT
Phathom Pharmaceuticals
PHAT
$708M
| $49.8K | ﹤0.01% |
3,000
-5,000
| -63% | -$71.4K |
|
5661
CALL
Playtika
PLTK
$1.52B
| $49.8K | ﹤0.01% |
12,600
+900
| +8% | +$3.52K |
|
5662
PUT
Gladstone Capital
GLAD
$422M
| $49.6K | ﹤0.01% |
2,400
+1,600
| +200% | +$32.4K |
|
5663
CALL
VanEck Bitcoin Trust
HODL
$1.05B
| $49.5K | ﹤0.01% |
+2,000
| New | +$56.6K |
|
5664
CALL
Hayward Holdings
HAYW
$3.21B
| $49.4K | ﹤0.01% |
3,200
-1,000
| -24% | -$15.8K |
|
5665
PUT
Krystal Biotech
KRYS
$10.1B
| $49.3K | ﹤0.01% |
200
-900
| -82% | -$189K |
|
5666
PUT
Sabra Healthcare REIT
SBRA
$5.34B
| $49.2K | ﹤0.01% |
2,600
+900
| +53% | +$16.7K |
|
5667
PUT
World Kinect Corp
WKC
$2.04B
| $49.2K | ﹤0.01% |
+2,100
| New | +$51.8K |
|
|
ZH
5668
PUT
Zhihu
ZH
$281M
| $49.2K | ﹤0.01% |
15,000
-83,700
| -85% | -$335K |
|
5669
PUT
Satellogic
SATL
$531M
| $49.2K | ﹤0.01% |
26,300
+23,200
| +748% | +$50.2K |
|
5670
Hawkins
HWKN
$2.67B
| $49.2K | ﹤0.01% |
+346
| New | +$50.9K |
|
|
ADBG
5671
Leverage Shares 2X Long ADBE Daily ETF
ADBG
$42M
| $49K | ﹤0.01% |
4,795
+4,495
| +1,498% | +$44.5K |
|
5672
PUT
Casella Waste Systems
CWST
$5.71B
| $49K | ﹤0.01% |
500
+300
| +150% | +$27.9K |
|
|
MNTN
5673
PUT
MNTN Inc
MNTN
$682M
| $49K | ﹤0.01% |
4,100
-8,800
| -68% | -$127K |
|
5674
PUT
CMS Energy
CMS
$22.6B
| $49K | ﹤0.01% |
700
+600
| +600% | +$43.6K |
|
5675
VanEck Social Sentiment ETF
BUZZ
$90.5M
| $48.9K | ﹤0.01% |
+1,506
| New | +$52.9K |
|
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.