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 | |
|---|---|---|---|---|---|---|
|
PEW
6601
PUT
GrabAGun Digital Holdings
PEW
$72.9M
| $17.5K | ﹤0.01% |
5,800
-48,400
| -89% | -$193K |
|
6602
CALL
Concrete Pumping Holdings
BBCP
$490M
| $17.4K | ﹤0.01% |
2,600
-2,100
| -45% | -$13.8K |
|
|
FPI
6603
CALL
Farmland Partners
FPI
$408M
| $17.4K | ﹤0.01% |
1,800
-1,600
| -47% | -$16K |
|
6604
PUT
Badger Meter
BMI
$3.89B
| $17.4K | ﹤0.01% |
100
-800
| -89% | -$144K |
|
6605
PUT
The Ensign Group
ENSG
$10.4B
| $17.4K | ﹤0.01% |
+100
| New | +$18K |
|
6606
PUT
Abeona Therapeutics
ABEO
$366M
| $17.4K | ﹤0.01% |
3,300
-63,600
| -95% | -$320K |
|
6607
Kforce
KFRC
$1.02B
| $17.4K | ﹤0.01% |
+562
| New | +$16.5K |
|
6608
CALL
Astrana Health
ASTH
$1.76B
| $17.4K | ﹤0.01% |
700
-400
| -36% | -$10.6K |
|
6609
CALL
ITT
ITT
$17.5B
| $17.4K | ﹤0.01% |
100
-900
| -90% | -$161K |
|
6610
VinFast Auto
VFS
$7.28B
| $17.3K | ﹤0.01% |
5,189
-21,937
| -81% | -$73.2K |
|
6611
Schwab Fundamental International Small Company Index ETF
FNDC
$3.05B
| $17.3K | ﹤0.01% |
+389
| New | +$17.3K |
|
6612
GraniteShares HIPS US High Income ETF
HIPS
$109M
| $17.3K | ﹤0.01% |
1,480
-1,665
| -53% | -$19.5K |
|
|
IRD
6613
PUT
Opus Genetics
IRD
$306M
| $17.3K | ﹤0.01% |
+8,600
| New | +$17.5K |
|
6614
PUT
AGF US Market Neutral Anti-Beta Fund
BTAL
$304M
| $17.3K | ﹤0.01% |
1,200
-2,000
| -63% | -$30.1K |
|
|
FLD
6615
PUT
Fold Holdings
FLD
$22.9M
| $17.2K | ﹤0.01% |
6,600
-29,200
| -82% | -$96.6K |
|
6616
CALL
Acacia Research
ACTG
$428M
| $17.2K | ﹤0.01% |
+4,600
| New | +$16.5K |
|
|
BIOA
6617
PUT
BioAge Labs
BIOA
$402M
| $17.2K | ﹤0.01% |
1,300
-146,000
| -99% | -$1.29M |
|
6618
PUT
Progress Software
PRGS
$1.66B
| $17.2K | ﹤0.01% |
400
-29,500
| -99% | -$1.29M |
|
|
ECG
6619
CALL
Everus Construction Group
ECG
$6.4B
| $17.1K | ﹤0.01% |
200
| – | – |
|
6620
PUT
FNB Corp
FNB
$6.73B
| $17.1K | ﹤0.01% |
1,000
-43,100
| -98% | -$704K |
|
6621
PUT
Allegiant Air
ALGT
$2.64B
| $17.1K | ﹤0.01% |
200
-600
| -75% | -$42.9K |
|
6622
CALL
Merchants Bancorp
MBIN
$2.53B
| $17K | ﹤0.01% |
500
-100
| -17% | -$3.28K |
|
6623
CALL
Mativ Holdings
MATV
$481M
| $17K | ﹤0.01% |
1,400
-100
| -7% | -$1.18K |
|
6624
E.W. Scripps
SSP
$257M
| $17K | ﹤0.01% |
4,261
-4,747
| -53% | -$16K |
|
6625
Lexicon Pharmaceuticals
LXRX
$1.03B
| $17K | ﹤0.01% |
14,758
-58,529
| -80% | -$80.4K |
|
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.