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 | |
|---|---|---|---|---|---|---|
2376
PUT
Euronet Worldwide
EEFT
$3.02B
| $1.29M | ﹤0.01% |
17,000
+2,100
| +14% | +$164K |
|
2377
PUT
ALPS REIT Dividend Dogs ETF
RDOG
$11.6M
| $1.29M | ﹤0.01% |
27,500
-13,200
| -32% | -$475K |
|
2378
CALL
Dave & Buster's
PLAY
$343M
| $1.29M | ﹤0.01% |
79,800
-31,600
| -28% | -$529K |
|
2379
iShares MSCI Europe Financials ETF
EUFN
$3.87B
| $1.29M | ﹤0.01% |
+34,876
| New | +$1.21M |
|
|
METU
2380
Direxion Daily META Bull 2X ETF
METU
$399M
| $1.29M | ﹤0.01% |
+40,176
| New | +$1.38M |
|
2381
Erasca
ERAS
$6.63B
| $1.29M | ﹤0.01% |
346,072
+234,735
| +211% | +$660K |
|
2382
Dollar General
DG
$25.9B
| $1.28M | ﹤0.01% |
9,674
-6,218
| -39% | -$694K |
|
2383
PUT
Quest Diagnostics
DGX
$25.1B
| $1.28M | ﹤0.01% |
7,400
-16,300
| -69% | -$2.97M |
|
2384
Expeditors International
EXPD
$22.9B
| $1.28M | ﹤0.01% |
+8,617
| New | +$1.17M |
|
2385
PUT
Elastic
ESTC
$6.1B
| $1.28M | ﹤0.01% |
17,000
-4,400
| -21% | -$359K |
|
2386
VanEck Rare Earth/Strategic Metals ETF
REMX
$2.03B
| $1.28M | ﹤0.01% |
17,334
+619
| +4% | +$44.4K |
|
2387
PUT
Interparfums
IPAR
$3.92B
| $1.28M | ﹤0.01% |
15,100
-500
| -3% | -$44K |
|
2388
PUT
Equifax
EFX
$20.3B
| $1.28M | ﹤0.01% |
5,900
-300
| -5% | -$65.7K |
|
|
MRSH
2389
PUT
Marsh
MRSH
$86.3B
| $1.28M | ﹤0.01% |
6,900
-8,600
| -55% | -$1.61M |
|
2390
PUT
Algoma Steel
ASTL
$455M
| $1.28M | ﹤0.01% |
312,100
-41,400
| -12% | -$165K |
|
2391
FuboTV Inc
FUBO
$245M
| $1.28M | ﹤0.01% |
42,307
+1,965
| +5% | +$78.4K |
|
2392
CALL
Crescent Energy
CRGY
$3.72B
| $1.28M | ﹤0.01% |
152,400
+111,800
| +275% | +$982K |
|
2393
PUT
G-III Apparel Group
GIII
$1.47B
| $1.28M | ﹤0.01% |
44,100
-21,900
| -33% | -$625K |
|
2394
PUT
Aehr Test Systems
AEHR
$2.48B
| $1.28M | ﹤0.01% |
63,200
-14,900
| -19% | -$360K |
|
2395
Telephone and Data Systems
TDS
$3.91B
| $1.28M | ﹤0.01% |
31,116
+21,547
| +225% | +$839K |
|
2396
CALL
Stratasys
SSYS
$697M
| $1.28M | ﹤0.01% |
146,900
-56,600
| -28% | -$561K |
|
|
JMIA
2397
CALL
Jumia Technologies
JMIA
$726M
| $1.27M | ﹤0.01% |
101,900
-89,900
| -47% | -$1.04M |
|
2398
NexGen Energy
NXE
$6.05B
| $1.27M | ﹤0.01% |
138,119
-183,679
| -57% | -$1.62M |
|
|
FIGR
2399
PUT
Figure Technology Solutions
FIGR
$6.1B
| $1.27M | ﹤0.01% |
31,000
-37,100
| -54% | -$1.48M |
|
2400
Zymeworks
ZYME
$1.68B
| $1.26M | ﹤0.01% |
48,040
+19,279
| +67% | +$421K |
|
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.