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 | |
|---|---|---|---|---|---|---|
6451
CALL
CPI Aerostructures
CVU
$66.2M
| $20.6K | ﹤0.01% |
+5,200
| New | +$14.2K |
|
6452
CALL
RB Global
RBA
$20.4B
| $20.6K | ﹤0.01% |
200
-13,700
| -99% | -$1.39M |
|
6453
CALL
Acadia Realty Trust
AKR
$3.09B
| $20.5K | ﹤0.01% |
1,000
+900
| +900% | +$17.9K |
|
|
ATYR
6454
aTyr Pharma
ATYR
$47.6M
| $20.5K | ﹤0.01% |
+26,227
| New | +$21.5K |
|
6455
PUT
Bank of Hawaii
BOH
$3.15B
| $20.5K | ﹤0.01% |
300
-200
| -40% | -$13.2K |
|
6456
PUT
Enanta Pharmaceuticals
ENTA
$366M
| $20.5K | ﹤0.01% |
1,300
-8,500
| -87% | -$108K |
|
6457
PUT
CVR Partners
UAN
$1.36B
| $20.5K | ﹤0.01% |
200
-2,400
| -92% | -$228K |
|
6458
CALL
Weave Communications
WEAV
$520M
| $20.5K | ﹤0.01% |
2,700
+2,500
| +1,250% | +$16.6K |
|
6459
CarParts.com
PRTS
$43.7M
| $20.5K | ﹤0.01% |
4,093
+2,925
| +250% | +$16.4K |
|
6460
Rekor Systems
REKR
$85.8M
| $20.5K | ﹤0.01% |
14,826
-50,427
| -77% | -$103K |
|
6461
CALL
Monte Rosa Therapeutics
GLUE
$1.4B
| $20.4K | ﹤0.01% |
1,300
-38,000
| -97% | -$512K |
|
6462
Ally Financial
ALLY
$13.2B
| $20.4K | ﹤0.01% |
+450
| New | +$18.5K |
|
|
RAL
6463
PUT
Ralliant Corp
RAL
$7.23B
| $20.4K | ﹤0.01% |
+400
| New | +$18.7K |
|
6464
PUT
Valvoline
VVV
$4.9B
| $20.3K | ﹤0.01% |
700
| – | – |
|
6465
CALL
Nexstar Media Group
NXST
$5.82B
| $20.3K | ﹤0.01% |
100
| – | – |
|
6466
PUT
Tactile Systems Technology
TCMD
$635M
| $20.3K | ﹤0.01% |
700
-100
| -13% | -$2.22K |
|
6467
Evolution Petroleum
EPM
$132M
| $20.3K | ﹤0.01% |
5,733
+4,009
| +233% | +$16.9K |
|
6468
New Fortress Energy
NFE
$92.1M
| $20.3K | ﹤0.01% |
17,778
-151,174
| -89% | -$223K |
|
6469
CALL
Jakks Pacific
JAKK
$301M
| $20.3K | ﹤0.01% |
1,200
+100
| +9% | +$1.73K |
|
|
XRN
6470
CALL
Chiron Real Estate Inc
XRN
$514M
| $20.2K | ﹤0.01% |
600
-8,500
| -93% | -$277K |
|
6471
CALL
Energy Recovery
ERII
$446M
| $20.2K | ﹤0.01% |
1,500
-8,600
| -85% | -$130K |
|
|
OMAH
6472
VistaShares Target 15 Berkshire Select Income ETF
OMAH
$949M
| $20.1K | ﹤0.01% |
+1,073
| New | +$20.4K |
|
6473
Skyward Specialty Insurance
SKWD
$2.43B
| $20.1K | ﹤0.01% |
393
-184
| -32% | -$8.84K |
|
6474
CALL
Quad
QUAD
$536M
| $20.1K | ﹤0.01% |
3,200
+300
| +10% | +$1.76K |
|
6475
CALL
Accuray
ARAY
$32M
| $20K | ﹤0.01% |
+24,300
| New | +$30.3K |
|
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.