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 | |
|---|---|---|---|---|---|---|
|
WAY
3501
CALL
Waystar Holding Corp
WAY
$4.54B
| $409K | ﹤0.01% |
12,500
-66,800
| -84% | -$2.38M |
|
3502
PUT
XPEL
XPEL
$1.21B
| $409K | ﹤0.01% |
8,200
-900
| -10% | -$37.6K |
|
3503
Vista Energy
VIST
$7.16B
| $409K | ﹤0.01% |
8,399
-14,778
| -64% | -$668K |
|
3504
PUT
Janux Therapeutics
JANX
$915M
| $408K | ﹤0.01% |
29,600
+25,300
| +588% | +$595K |
|
|
FLNA
3505
PUT
Filana Therapeutics
FLNA
$42.7M
| $408K | ﹤0.01% |
200,900
+90,700
| +82% | +$290K |
|
3506
PUT
Nasdaq
NDAQ
$53.6B
| $408K | ﹤0.01% |
4,200
-61,700
| -94% | -$5.55M |
|
3507
Huazhu Hotels Group
HTHT
$13.2B
| $408K | ﹤0.01% |
8,661
+6,372
| +278% | +$275K |
|
3508
PUT
Matador Resources
MTDR
$5.73B
| $407K | ﹤0.01% |
9,600
-198,400
| -95% | -$8.33M |
|
|
EUAD
3509
Select STOXX Europe Aerospace & Defense ETF
EUAD
$1.18B
| $407K | ﹤0.01% |
+9,667
| New | +$417K |
|
3510
PUT
Idexx Laboratories
IDXX
$44.9B
| $406K | ﹤0.01% |
600
-3,400
| -85% | -$2.32M |
|
3511
PUT
Viper Energy
VNOM
$8.21B
| $406K | ﹤0.01% |
10,500
-9,700
| -48% | -$367K |
|
3512
Digital Turbine
APPS
$1.02B
| $406K | ﹤0.01% |
81,105
-20,407
| -20% | -$115K |
|
|
RC
3513
CALL
Ready Capital
RC
$261M
| $404K | ﹤0.01% |
185,100
+173,600
| +1,510% | +$486K |
|
|
SMST
3514
Defiance Daily Target 2x Short MSTR ETF
SMST
$28.9M
| $403K | ﹤0.01% |
+4,341
| New | +$242K |
|
3515
CALL
New York Times
NYT
$12.2B
| $403K | ﹤0.01% |
5,800
-4,200
| -42% | -$260K |
|
3516
PUT
Full Truck Alliance
YMM
$9.64B
| $402K | ﹤0.01% |
37,500
-244,200
| -87% | -$2.93M |
|
3517
CALL
PVH
PVH
$4.01B
| $402K | ﹤0.01% |
6,000
-9,300
| -61% | -$727K |
|
|
SII
3518
CALL
Sprott
SII
$2.73B
| $401K | ﹤0.01% |
4,100
-29,400
| -88% | -$2.61M |
|
3519
CALL
Comstock
LODE
$215M
| $401K | ﹤0.01% |
106,600
+89,500
| +523% | +$304K |
|
|
WW
3520
WW International
WW
$138M
| $399K | ﹤0.01% |
+13,667
| New | +$382K |
|
3521
CALL
Ring Energy
REI
$287M
| $399K | ﹤0.01% |
458,600
-106,800
| -19% | -$102K |
|
3522
PUT
iRadimed
IRMD
$1.21B
| $399K | ﹤0.01% |
4,100
+2,400
| +141% | +$206K |
|
3523
PUT
Lightwave Logic
LWLG
$887M
| $399K | ﹤0.01% |
123,000
+75,600
| +159% | +$335K |
|
|
NFGC
3524
CALL
New Found Gold
NFGC
$542M
| $398K | ﹤0.01% |
134,100
+38,200
| +40% | +$93.7K |
|
3525
PUT
Amcor
AMCR
$21.6B
| $398K | ﹤0.01% |
9,540
-3,900
| -29% | -$161K |
|
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.