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 | |
|---|---|---|---|---|---|---|
5776
CALL
DXP Enterprises
DXPE
$2.43B
| $43.9K | ﹤0.01% |
400
-4,100
| -91% | -$447K |
|
|
SLSR
5777
Solaris Resources
SLSR
$1.26B
| $43.9K | ﹤0.01% |
5,506
+4,728
| +608% | +$32.8K |
|
5778
PUT
STAAR Surgical
STAA
$1.21B
| $43.9K | ﹤0.01% |
1,900
+800
| +73% | +$20.6K |
|
5779
Defiance R2000 Weekly Distribution ETF
IWMY
$95.6M
| $43.8K | ﹤0.01% |
2,224
+665
| +43% | +$14.1K |
|
5780
PUT
FTAI Infrastructure
FIP
$441M
| $43.8K | ﹤0.01% |
9,500
-5,600
| -37% | -$27.6K |
|
|
SMCY
5781
YieldMax SMCI Option Income Strategy ETF
SMCY
$105M
| $43.8K | ﹤0.01% |
5,406
-1,982
| -27% | -$23.7K |
|
5782
iShares 0-1 Year Treasury Bond ETF
SHV
$20.8B
| $43.7K | ﹤0.01% |
397
+290
| +271% | +$32K |
|
|
MAPS
5783
PUT
DELISTED
WM TECHNOLOGY INC A
MAPS
| $43.7K | ﹤0.01% |
+53,000
| New | +$52.2K |
|
5784
CALL
MYR Group
MYRG
$5.19B
| $43.7K | ﹤0.01% |
200
-500
| -71% | -$109K |
|
5785
CALL
Electromed
ELMD
$337M
| $43.7K | ﹤0.01% |
1,500
+1,400
| +1,400% | +$36.7K |
|
5786
PUT
Nurix Therapeutics
NRIX
$2.41B
| $43.6K | ﹤0.01% |
+2,300
| New | +$33K |
|
5787
CALL
Utz Brands
UTZ
$1.25B
| $43.6K | ﹤0.01% |
4,200
+1,700
| +68% | +$18.3K |
|
5788
Civeo
CVEO
$345M
| $43.4K | ﹤0.01% |
+1,897
| New | +$42.1K |
|
5789
PUT
Red Rock Resorts
RRR
$3.77B
| $43.4K | ﹤0.01% |
700
+600
| +600% | +$35.1K |
|
5790
CALL
Viant Technology
DSP
$236M
| $43.3K | ﹤0.01% |
3,600
+800
| +29% | +$7.99K |
|
5791
CALL
CVRx
CVRX
$137M
| $43.3K | ﹤0.01% |
6,100
+5,600
| +1,120% | +$51.1K |
|
5792
PBF Energy
PBF
$8.57B
| $43.3K | ﹤0.01% |
+1,597
| New | +$51.1K |
|
5793
PUT
Emergent Biosolutions
EBS
$373M
| $43.3K | ﹤0.01% |
3,500
+1,600
| +84% | +$17.1K |
|
5794
iShares US Medical Devices ETF
IHI
$3.13B
| $43.3K | ﹤0.01% |
+696
| New | +$43K |
|
5795
CALL
Kite Realty
KRG
$5.81B
| $43.1K | ﹤0.01% |
1,800
-1,000
| -36% | -$22.7K |
|
5796
PUT
Dominari Holdings
DOMH
$57.4M
| $43.1K | ﹤0.01% |
8,700
+1,200
| +16% | +$6.13K |
|
5797
PUT
Editas Medicine
EDIT
$396M
| $43K | ﹤0.01% |
21,000
-8,300
| -28% | -$24K |
|
5798
PUT
KB Financial Group
KB
$41.4B
| $43K | ﹤0.01% |
500
-500
| -50% | -$42.1K |
|
5799
Amplify Cybersecurity ETF
HACK
$2.68B
| $43K | ﹤0.01% |
+535
| New | +$45.4K |
|
5800
PUT
RCI Hospitality Holdings
RICK
$192M
| $42.9K | ﹤0.01% |
1,800
-16,000
| -90% | -$410K |
|
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.