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 | |
|---|---|---|---|---|---|---|
4376
CALL
Cousins Properties
CUZ
$5.31B
| $173K | ﹤0.01% |
+6,700
| New | +$174K |
|
4377
MSCI
MSCI
$42.4B
| $173K | ﹤0.01% |
301
-3,768
| -93% | -$2.11M |
|
4378
PUT
Imperial Oil
IMO
$62.3B
| $173K | ﹤0.01% |
2,000
-2,200
| -52% | -$200K |
|
4379
PUT
Illinois Tool Works
ITW
$84.1B
| $172K | ﹤0.01% |
700
-2,800
| -80% | -$698K |
|
4380
CareDx
CDNA
$1.83B
| $172K | ﹤0.01% |
9,141
+4,554
| +99% | +$76.3K |
|
4381
CALL
Mueller Industries
MLI
$14.5B
| $172K | ﹤0.01% |
3,000
+2,600
| +650% | +$140K |
|
4382
PUT
FT Vest Gold Strategy Target Income ETF
IGLD
$508M
| $172K | ﹤0.01% |
6,300
+1,900
| +43% | +$47.5K |
|
4383
CALL
Carter's
CRI
$1.43B
| $172K | ﹤0.01% |
5,300
-9,000
| -63% | -$281K |
|
4384
CALL
US Physical Therapy
USPH
$1.22B
| $172K | ﹤0.01% |
+2,200
| New | +$179K |
|
4385
Kodiak Sciences
KOD
$2.5B
| $171K | ﹤0.01% |
6,133
-7,745
| -56% | -$159K |
|
4386
CALL
Twist Bioscience
TWST
$5.32B
| $171K | ﹤0.01% |
5,400
-8,900
| -62% | -$278K |
|
4387
Reynolds Consumer Products
REYN
$5.42B
| $171K | ﹤0.01% |
7,471
-11,113
| -60% | -$268K |
|
4388
PUT
Rayonier
RYN
$6.67B
| $171K | ﹤0.01% |
7,900
+7,166
| +976% | +$162K |
|
4389
CALL
Steven Madden
SHOO
$3.17B
| $171K | ﹤0.01% |
4,100
+2,200
| +116% | +$84.9K |
|
4390
Progyny
PGNY
$2.46B
| $171K | ﹤0.01% |
6,648
+5,981
| +897% | +$138K |
|
4391
Global X Blockchain ETF
BKCH
$192M
| $171K | ﹤0.01% |
2,670
+2,258
| +548% | +$198K |
|
|
TTAN
4392
PUT
ServiceTitan Inc
TTAN
$8.03B
| $170K | ﹤0.01% |
1,600
-2,100
| -57% | -$205K |
|
|
WAY
4393
Waystar Holding Corp
WAY
$4.7B
| $170K | ﹤0.01% |
+5,203
| New | +$185K |
|
4394
CALL
Wheels Up
UP
$203M
| $170K | ﹤0.01% |
12,970
+5,340
| +70% | +$122K |
|
4395
PUT
SEALSQ Corp
LAES
$501M
| $170K | ﹤0.01% |
45,000
-84,400
| -65% | -$430K |
|
4396
CALL
Ameren
AEE
$30.4B
| $170K | ﹤0.01% |
1,700
+1,500
| +750% | +$154K |
|
|
HITI
4397
High Tide
HITI
$180M
| $170K | ﹤0.01% |
+64,033
| New | +$190K |
|
4398
CALL
ManpowerGroup
MAN
$2.6B
| $169K | ﹤0.01% |
5,700
-200
| -3% | -$6.25K |
|
4399
iShares Copper and Metals Mining ETF
ICOP
$416M
| $169K | ﹤0.01% |
+3,824
| New | +$152K |
|
4400
Vanguard Morningstar Growth ETF
VUG
$212B
| $169K | ﹤0.01% |
2,082
-8,394
| -80% | -$681K |
|
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.