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 | |
|---|---|---|---|---|---|---|
5826
Ameresco
AMRC
$1.12B
| $41.9K | ﹤0.01% |
1,429
-2,780
| -66% | -$97.6K |
|
5827
PUT
Candel Therapeutics
CADL
$733M
| $41.8K | ﹤0.01% |
7,400
+4,900
| +196% | +$26.4K |
|
5828
eGain
EGAN
$187M
| $41.8K | ﹤0.01% |
4,063
+2,066
| +103% | +$24.7K |
|
5829
CALL
Sprott Junior Gold Miners ETF
SGDJ
$267M
| $41.8K | ﹤0.01% |
600
+500
| +500% | +$39.3K |
|
5830
PUT
Rocket Pharmaceuticals
RCKT
$340M
| $41.8K | ﹤0.01% |
11,900
-8,200
| -41% | -$28.1K |
|
5831
PUT
Bakkt Inc
BKKT
$321M
| $41.7K | ﹤0.01% |
5,700
-11,200
| -66% | -$248K |
|
5832
PUT
Fidelity Enhanced Large Cap Value ETF
FELV
$3.27B
| $41.7K | ﹤0.01% |
1,000
| – | – |
|
5833
PUT
QuinStreet
QNST
$890M
| $41.7K | ﹤0.01% |
2,900
-11,600
| -80% | -$167K |
|
5834
CALL
RPM International
RPM
$13.7B
| $41.6K | ﹤0.01% |
400
-2,600
| -87% | -$281K |
|
|
PTRN
5835
PUT
Pattern Group Inc
PTRN
$4.07B
| $41.5K | ﹤0.01% |
+3,600
| New | +$52.4K |
|
5836
PUT
Regency Centers
REG
$14.7B
| $41.4K | ﹤0.01% |
+600
| New | +$42.1K |
|
5837
CALL
Westwater Resources
WWR
$52.4M
| $41.4K | ﹤0.01% |
55,200
+18,500
| +50% | +$23K |
|
5838
PUT
Eagle Materials
EXP
$6.29B
| $41.3K | ﹤0.01% |
200
| – | – |
|
5839
CALL
Ardmore Shipping
ASC
$710M
| $41.3K | ﹤0.01% |
3,900
-36,900
| -90% | -$439K |
|
5840
PUT
Associated Banc-Corp
ASB
$5.83B
| $41.2K | ﹤0.01% |
1,600
-1,200
| -43% | -$30.9K |
|
5841
CapForce IBD 50 ETF
FFTY
$79.5M
| $41.2K | ﹤0.01% |
+1,184
| New | +$43.7K |
|
5842
PTC Therapeutics
PTCT
$5.68B
| $41.1K | ﹤0.01% |
541
-8,385
| -94% | -$609K |
|
5843
PUT
Viavi Solutions
VIAV
$9.12B
| $41K | ﹤0.01% |
2,300
-2,700
| -54% | -$43.6K |
|
|
PLG
5844
PUT
Platinum Group Metals
PLG
$164M
| $40.8K | ﹤0.01% |
17,300
+13,800
| +394% | +$33.3K |
|
5845
Enliven Therapeutics
ELVN
$3.92B
| $40.8K | ﹤0.01% |
2,649
+2,480
| +1,467% | +$49.4K |
|
5846
CALL
Immix Biopharma
IMMX
$592M
| $40.8K | ﹤0.01% |
+7,800
| New | +$32.1K |
|
5847
PUT
Nexstar Media Group
NXST
$5.82B
| $40.6K | ﹤0.01% |
200
-3,000
| -94% | -$586K |
|
|
DSL
5848
PUT
DoubleLine Income Solutions Fund
DSL
$1.22B
| $40.6K | ﹤0.01% |
3,600
-100
| -3% | -$1.16K |
|
|
NTSK
5849
Netskope Inc
NTSK
$5.09B
| $40.6K | ﹤0.01% |
+2,313
| New | +$48.3K |
|
5850
CALL
EverQuote
EVER
$892M
| $40.5K | ﹤0.01% |
1,500
-10,200
| -87% | -$247K |
|
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.