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 | |
|---|---|---|---|---|---|---|
3476
CALL
Kimco Realty
KIM
$17.7B
| $422K | ﹤0.01% |
20,800
-6,100
| -23% | -$127K |
|
|
NAVN
3477
Navan Inc
NAVN
$6.7B
| $422K | ﹤0.01% |
+24,683
| New | +$392K |
|
3478
PUT
Winnebago Industries
WGO
$908M
| $421K | ﹤0.01% |
10,400
-52,700
| -84% | -$1.92M |
|
3479
CALL
Corpay
CPAY
$25.1B
| $421K | ﹤0.01% |
1,400
| – | – |
|
3480
PUT
Frontier Group Holdings
ULCC
$1.43B
| $421K | ﹤0.01% |
+89,400
| New | +$396K |
|
3481
PUT
Genius Sports
GENI
$1.95B
| $421K | ﹤0.01% |
38,200
-35,600
| -48% | -$388K |
|
|
ETHW
3482
Bitwise Ethereum ETF
ETHW
$201M
| $419K | ﹤0.01% |
19,683
-45,385
| -70% | -$1.12M |
|
|
TPC
3483
Tutor Perini Cor
TPC
$4.31B
| $419K | ﹤0.01% |
+6,245
| New | +$410K |
|
3484
Natural Gas Services Group
NGS
$460M
| $418K | ﹤0.01% |
+12,432
| New | +$371K |
|
3485
CALL
Graco
GGG
$13.3B
| $418K | ﹤0.01% |
5,100
+4,200
| +467% | +$346K |
|
3486
PUT
Brookfield
BN
$104B
| $418K | ﹤0.01% |
9,100
-69,650
| -88% | -$3.18M |
|
3487
PUT
AvalonBay Communities
AVB
$27.2B
| $417K | ﹤0.01% |
2,300
+2,100
| +1,050% | +$381K |
|
3488
Portillo's
PTLO
$339M
| $417K | ﹤0.01% |
91,846
-70,183
| -43% | -$366K |
|
3489
CALL
Alector
ALEC
$169M
| $417K | ﹤0.01% |
267,200
+229,700
| +613% | +$408K |
|
3490
CALL
Genmab
GMAB
$17.8B
| $416K | ﹤0.01% |
13,500
-2,400
| -15% | -$74.8K |
|
3491
PUT
Aquestive Therapeutics
AQST
$472M
| $415K | ﹤0.01% |
64,300
-7,000
| -10% | -$43.6K |
|
|
SOGP
3492
PUT
Sound Group
SOGP
$51.3M
| $415K | ﹤0.01% |
35,700
-47,800
| -57% | -$674K |
|
3493
SEALSQ Corp
LAES
$521M
| $413K | ﹤0.01% |
109,317
+70,615
| +182% | +$360K |
|
3494
Adecoagro
AGRO
$1.45B
| $413K | ﹤0.01% |
52,107
+49,596
| +1,975% | +$389K |
|
3495
CALL
Lionsgate Studios
LION
$3.85B
| $412K | ﹤0.01% |
45,100
-95,700
| -68% | -$681K |
|
3496
CALL
Skywest
SKYW
$4.51B
| $412K | ﹤0.01% |
4,100
+2,500
| +156% | +$250K |
|
|
TBCH
3497
CALL
Turtle Beach Corp
TBCH
$258M
| $411K | ﹤0.01% |
29,300
-2,000
| -6% | -$29.7K |
|
3498
PUT
L3Harris
LHX
$56.9B
| $411K | ﹤0.01% |
1,400
-11,600
| -89% | -$3.35M |
|
3499
CALL
ODDITY Tech
ODD
$784M
| $410K | ﹤0.01% |
10,200
+3,400
| +50% | +$154K |
|
3500
PUT
Box
BOX
$4.36B
| $410K | ﹤0.01% |
13,700
-77,900
| -85% | -$2.44M |
|
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.