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 | |
|---|---|---|---|---|---|---|
6401
CALL
Hillman Solutions
HLMN
$1.54B
| $21.6K | ﹤0.01% |
2,500
+1,500
| +150% | +$13.5K |
|
6402
Backblaze
BLZE
$823M
| $21.6K | ﹤0.01% |
+4,642
| New | +$31.8K |
|
6403
CALL
Nature's Sunshine
NATR
$354M
| $21.6K | ﹤0.01% |
+1,000
| New | +$18.3K |
|
6404
PUT
Madison Square Garden
MSGE
$3.65B
| $21.6K | ﹤0.01% |
400
-100
| -20% | -$4.81K |
|
6405
Worthington Enterprises
WOR
$2.75B
| $21.6K | ﹤0.01% |
418
-2,010
| -83% | -$111K |
|
6406
PUT
Hagerty
HGTY
$1.17B
| $21.5K | ﹤0.01% |
1,600
+900
| +129% | +$11.2K |
|
6407
CALL
Global Net Lease
GNL
$1.84B
| $21.5K | ﹤0.01% |
2,500
-271,600
| -99% | -$2.18M |
|
6408
CALL
Five Star Bancorp
FSBC
$1.14B
| $21.5K | ﹤0.01% |
+600
| New | +$20.8K |
|
6409
Commerce Bancshares
CBSH
$8.53B
| $21.5K | ﹤0.01% |
+410
| New | +$21.4K |
|
6410
CALL
AZZ Inc
AZZ
$4.35B
| $21.4K | ﹤0.01% |
200
-100
| -33% | -$10.4K |
|
6411
CALL
Xencor
XNCR
$1.5B
| $21.4K | ﹤0.01% |
1,400
-4,500
| -76% | -$67.2K |
|
|
CADE
6412
PUT
DELISTED
Cadence Bank
CADE
| $21.4K | ﹤0.01% |
500
| – | – |
|
6413
Wabash National
WNC
$512M
| $21.4K | ﹤0.01% |
+2,476
| New | +$21.6K |
|
6414
Red Violet
RDVT
$979M
| $21.4K | ﹤0.01% |
376
+328
| +683% | +$17.8K |
|
6415
Unifirst Corp
UNF
$5.3B
| $21.4K | ﹤0.01% |
+111
| New | +$18.7K |
|
6416
Myomo
MYO
$39M
| $21.4K | ﹤0.01% |
23,517
+23,487
| +78,290% | +$22.5K |
|
6417
La-Z-Boy
LZB
$1.58B
| $21.4K | ﹤0.01% |
+574
| New | +$20.1K |
|
6418
PUT
Quanterix
QTRX
$164M
| $21.4K | ﹤0.01% |
4,200
| – | – |
|
6419
CALL
Goldman Sachs BDC
GSBD
$969M
| $21.3K | ﹤0.01% |
2,300
+1,000
| +77% | +$9.81K |
|
6420
CALL
Privia Health
PRVA
$2.98B
| $21.3K | ﹤0.01% |
+900
| New | +$21.9K |
|
6421
ProShares UltraPro Short Russell2000
SRTY
$79.9M
| $21.3K | ﹤0.01% |
502
-8
| -2% | -$353 |
|
6422
Descartes Systems
DSGX
$6.44B
| $21.3K | ﹤0.01% |
243
-878
| -78% | -$78.5K |
|
6423
PUT
Yelp
YELP
$1.45B
| $21.3K | ﹤0.01% |
700
| – | – |
|
6424
CALL
Arcosa
ACA
$7.13B
| $21.3K | ﹤0.01% |
200
-400
| -67% | -$40.4K |
|
6425
Smith & Wesson
SWBI
$651M
| $21.3K | ﹤0.01% |
2,153
-74,796
| -97% | -$722K |
|
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.