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 | |
|---|---|---|---|---|---|---|
526
PUT
Kimberly-Clark
KMB
$36.1B
| $22M | 0.01% |
218,000
+203,700
| +1,424% | +$22.3M |
|
527
PUT
Cameco
CCJ
$39.4B
| $22M | 0.01% |
240,200
-188,600
| -44% | -$17M |
|
|
GAP
528
CALL
The Gap Inc
GAP
$7.07B
| $22M | 0.01% |
858,300
+336,900
| +65% | +$8.16M |
|
529
CALL
Coupang
CPNG
$28.1B
| $22M | 0.01% |
930,500
+202,000
| +28% | +$5.75M |
|
530
PUT
RH
RH
$3.31B
| $21.9M | 0.01% |
122,400
+18,200
| +17% | +$3.11M |
|
531
PUT
Intuit
INTU
$77.8B
| $21.9M | 0.01% |
33,100
-3,200
| -9% | -$2.11M |
|
532
PUT
MP Materials
MP
$8.13B
| $21.9M | 0.01% |
433,200
-202,100
| -32% | -$12.8M |
|
533
PUT
Biogen
BIIB
$29.2B
| $21.5M | 0.01% |
122,300
+92,800
| +315% | +$15.2M |
|
534
CALL
KKR & Co
KKR
$85.8B
| $21.5M | 0.01% |
168,800
-52,400
| -24% | -$6.52M |
|
535
CALL
State Street SPDR Portfolio Short Term Treasury ETF
SPTS
$6.06B
| $21.4M | 0.01% |
205,300
+33,300
| +19% | +$976K |
|
536
PUT
US Bancorp Series B Preferred Stock
USB.PRH
$747M
| $21.3M | 0.01% |
399,400
+63,300
| +19% | +$1.19M |
|
537
VanEck Gold Miners ETF
GDX
$23.4B
| $21.2M | 0.01% |
+247,615
| New | +$19.6M |
|
538
PUT
Deere & Co
DE
$164B
| $21.2M | 0.01% |
45,500
-7,400
| -14% | -$3.47M |
|
539
CALL
Rio Tinto
RIO
$150B
| $21M | 0.01% |
262,500
+50,600
| +24% | +$3.64M |
|
540
CALL
Amphenol
APH
$194B
| $21M | 0.01% |
155,300
-46,500
| -23% | -$6.22M |
|
541
PUT
CleanSpark
CLSK
$3.93B
| $20.9M | 0.01% |
2,063,600
-784,700
| -28% | -$11.8M |
|
542
Marvell Technology
MRVL
$189B
| $20.9M | 0.01% |
245,442
-73,018
| -23% | -$6.39M |
|
543
CALL
Archer Aviation
ACHR
$3.95B
| $20.6M | 0.01% |
2,743,100
-117,400
| -4% | -$1.1M |
|
544
CALL
Eaton
ETN
$158B
| $20.5M | 0.01% |
64,300
-24,500
| -28% | -$8.68M |
|
545
CALL
Stanley Black & Decker
SWK
$13.9B
| $20.4M | 0.01% |
274,900
+53,400
| +24% | +$3.76M |
|
546
PUT
Pinterest
PINS
$12.6B
| $20.4M | 0.01% |
787,700
+6,700
| +0.9% | +$193K |
|
547
Warner Bros
WBD
$64.8B
| $20.4M | 0.01% |
707,385
+241,689
| +52% | +$5.65M |
|
548
Coinbase
COIN
$43.8B
| $20.2M | 0.01% |
89,109
+31,185
| +54% | +$9.29M |
|
|
SNDK
549
CALL
Sandisk
SNDK
$237B
| $20.1M | 0.01% |
84,600
-106,900
| -56% | -$21.4M |
|
550
CALL
Nextpower Inc
NXT
$15.9B
| $20M | 0.01% |
229,200
+50,100
| +28% | +$4.54M |
|
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.