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 | |
|---|---|---|---|---|---|---|
2501
PUT
Guidewire Software
GWRE
$11.5B
| $1.15M | ﹤0.01% |
5,700
+4,200
| +280% | +$929K |
|
|
NXDR
2502
CALL
Nextdoor Holdings
NXDR
$835M
| $1.15M | ﹤0.01% |
545,500
+170,800
| +46% | +$335K |
|
2503
Globus Medical
GMED
$10.4B
| $1.15M | ﹤0.01% |
13,118
+10,749
| +454% | +$816K |
|
2504
Procure Space ETF
UFO
$620M
| $1.14M | ﹤0.01% |
29,616
+28,174
| +1,954% | +$1.03M |
|
2505
CALL
Arcus Biosciences
RCUS
$3.57B
| $1.14M | ﹤0.01% |
48,000
-1,900
| -4% | -$38.8K |
|
2506
Uranium Energy
UEC
$4.71B
| $1.14M | ﹤0.01% |
97,892
-152,778
| -61% | -$2M |
|
2507
CALL
Triple Flag Precious Metals
TFPM
$6B
| $1.14M | ﹤0.01% |
34,400
+13,200
| +62% | +$413K |
|
|
HNGE
2508
CALL
Hinge Health
HNGE
$5.75B
| $1.14M | ﹤0.01% |
24,600
-9,400
| -28% | -$453K |
|
2509
PUT
Vanguard Short-Term Treasury ETF
VGSH
$29.3B
| $1.14M | ﹤0.01% |
16,800
-10,100
| -38% | -$594K |
|
2510
CALL
Newell Brands
NWL
$2.16B
| $1.14M | ﹤0.01% |
306,600
+24,200
| +9% | +$97.8K |
|
2511
PUT
VinFast Auto
VFS
$6.67B
| $1.14M | ﹤0.01% |
341,400
-3,700
| -1% | -$12.3K |
|
2512
Unum
UNM
$13.8B
| $1.14M | ﹤0.01% |
14,703
-14,622
| -50% | -$1.12M |
|
2513
CALL
BorgWarner
BWA
$13.2B
| $1.14M | ﹤0.01% |
25,200
-54,600
| -68% | -$2.39M |
|
2514
Crane Co
CR
$13.1B
| $1.13M | ﹤0.01% |
+6,151
| New | +$1.14M |
|
|
VNET
2515
CALL
VNET Group
VNET
$2.05B
| $1.13M | ﹤0.01% |
134,000
-511,400
| -79% | -$4.74M |
|
|
SARO
2516
CALL
StandardAero Inc
SARO
$9.54B
| $1.13M | ﹤0.01% |
39,500
+26,200
| +197% | +$713K |
|
2517
Air Products & Chemicals
APD
$66.3B
| $1.13M | ﹤0.01% |
+4,564
| New | +$1.16M |
|
2518
CALL
Camtek
CAMT
$6.9B
| $1.13M | ﹤0.01% |
10,600
-7,300
| -41% | -$820K |
|
2519
CALL
Banco Macro
BMA
$5.7B
| $1.13M | ﹤0.01% |
12,500
+8,400
| +205% | +$635K |
|
2520
PUT
Trex
TREX
$4.51B
| $1.13M | ﹤0.01% |
32,100
+24,100
| +301% | +$975K |
|
2521
PUT
ING
ING
$93.8B
| $1.13M | ﹤0.01% |
40,200
+23,900
| +147% | +$616K |
|
2522
CALL
Corebridge Financial
CRBG
$14.1B
| $1.13M | ﹤0.01% |
37,300
-11,000
| -23% | -$338K |
|
|
DVAX
2523
CALL
DELISTED
Dynavax Technologies
DVAX
| $1.12M | ﹤0.01% |
72,800
+35,200
| +94% | +$388K |
|
2524
CALL
Alcon
ALC
$33.1B
| $1.12M | ﹤0.01% |
14,200
+1,400
| +11% | +$108K |
|
|
TGB
2525
Trekor Metals
TGB
$2.56B
| $1.12M | ﹤0.01% |
197,585
+26,721
| +16% | +$126K |
|
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.