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 | |
|---|---|---|---|---|---|---|
5226
CALL
Clear Channel Outdoor Holdings
CCO
$1.23B
| $79.6K | ﹤0.01% |
36,000
+31,600
| +718% | +$58.6K |
|
5227
Hafnia
HAFN
$3.84B
| $79.5K | ﹤0.01% |
+14,919
| New | +$89K |
|
|
CRMG
5228
Leverage Shares 2X Long CRM Daily ETF
CRMG
$58.7M
| $79.5K | ﹤0.01% |
5,799
+3,996
| +222% | +$49.5K |
|
5229
PUT
U-Haul Holding Co Series N
UHAL.B
$12.2B
| $79.5K | ﹤0.01% |
1,700
-37,900
| -96% | -$1.84M |
|
5230
PUT
Zai Lab
ZLAB
$2.06B
| $79.4K | ﹤0.01% |
4,500
+2,100
| +88% | +$49.2K |
|
5231
Build-A-Bear
BBW
$425M
| $79.3K | ﹤0.01% |
+1,295
| New | +$70.5K |
|
5232
PUT
Steven Madden
SHOO
$3.37B
| $79.1K | ﹤0.01% |
1,900
-2,200
| -54% | -$84.9K |
|
|
TUYA
5233
Tuya Inc
TUYA
$1.03B
| $79.1K | ﹤0.01% |
37,496
-142,895
| -79% | -$326K |
|
5234
GrowGeneration
GRWG
$86.5M
| $79K | ﹤0.01% |
52,639
-44,928
| -46% | -$73.8K |
|
5235
Haleon
HLN
$43.5B
| $78.9K | ﹤0.01% |
+7,800
| New | +$74.1K |
|
|
NMG
5236
Nouveau Monde Graphite
NMG
$428M
| $78.8K | ﹤0.01% |
31,787
+24,110
| +314% | +$70.6K |
|
|
CYPH
5237
Cypherpunk Technologies Inc
CYPH
$62.9M
| $78.7K | ﹤0.01% |
67,818
+62,769
| +1,243% | +$68.6K |
|
5238
PUT
Kopin
KOPN
$652M
| $78.6K | ﹤0.01% |
33,600
-9,100
| -21% | -$26.3K |
|
|
CTLP
5239
CALL
DELISTED
Cantaloupe
CTLP
| $78.6K | ﹤0.01% |
7,400
-2,100
| -22% | -$22.3K |
|
5240
PUT
Trupanion
TRUP
$1.07B
| $78.5K | ﹤0.01% |
2,100
-200
| -9% | -$7.86K |
|
5241
CALL
H&R Block
HRB
$5.58B
| $78.4K | ﹤0.01% |
1,800
-1,600
| -47% | -$74.8K |
|
5242
Agilon Health
AGL
$1.53B
| $78.3K | ﹤0.01% |
4,546
+910
| +25% | +$17.6K |
|
5243
PUT
Kinsale Capital Group
KNSL
$8.12B
| $78.2K | ﹤0.01% |
200
-100
| -33% | -$40.8K |
|
|
NKLR
5244
CALL
Terra Innovatum Global N.V.
NKLR
$568M
| $78.1K | ﹤0.01% |
+16,900
| New | +$119K |
|
5245
Corsair Gaming
CRSR
$1.13B
| $78.1K | ﹤0.01% |
13,142
-67,762
| -84% | -$471K |
|
5246
PUT
Alliant Energy
LNT
$18.3B
| $78K | ﹤0.01% |
1,200
+600
| +100% | +$40.2K |
|
5247
Orthofix Medical
OFIX
$477M
| $78K | ﹤0.01% |
5,143
-359
| -7% | -$5.48K |
|
5248
CALL
Westlake Chemical Partners
WLKP
$763M
| $77.9K | ﹤0.01% |
4,100
+300
| +8% | +$5.79K |
|
5249
Vanguard Long-Term Corporate Bond ETF
VCLT
$8.81B
| $77.9K | ﹤0.01% |
1,027
+563
| +121% | +$43.4K |
|
|
BCYC
5250
PUT
Bicycle Therapeutics
BCYC
$269M
| $77.9K | ﹤0.01% |
11,000
+10,100
| +1,122% | +$74.5K |
|
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.