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 | |
|---|---|---|---|---|---|---|
7476
PUT
Pacer Trendpilot US Large Cap ETF
PTLC
$3.19B
| $4.66K | ﹤0.01% |
100
-200
| -67% | -$11.1K |
|
7477
Gerdau
GGB
$9.54B
| $4.63K | ﹤0.01% |
1,254
-4,006
| -76% | -$14K |
|
7478
CALL
RAVE Restaurant Group
RAVE
$42.8M
| $4.62K | ﹤0.01% |
+1,400
| New | +$4.05K |
|
7479
CALL
Vaxcyte
PCVX
$7.65B
| $4.61K | ﹤0.01% |
100
-66,700
| -100% | -$2.98M |
|
|
XOMA
7480
DELISTED
Xoma
XOMA
| $4.6K | ﹤0.01% |
173
+2
| +1% | +$64 |
|
7481
Enact Holdings
ACT
$6.75B
| $4.6K | ﹤0.01% |
116
-330
| -74% | -$12.4K |
|
|
NEXN
7482
PUT
Nexxen International
NEXN
$588M
| $4.58K | ﹤0.01% |
+700
| New | +$5.21K |
|
7483
CALL
RE/MAX Holdings
RMAX
$198M
| $4.55K | ﹤0.01% |
600
-6,300
| -91% | -$51.1K |
|
7484
PUT
NewtekOne
NEWT
$426M
| $4.54K | ﹤0.01% |
400
-3,600
| -90% | -$39.3K |
|
|
IONZ
7485
Defiance Daily Target 2x Short IONQ ETF
IONZ
$13M
| $4.53K | ﹤0.01% |
+200
| New | +$4.67K |
|
7486
Direxion Daily MSCI Emerging Markets Bull 3X ETF
EDC
$131M
| $4.53K | ﹤0.01% |
83
+50
| +152% | +$2.64K |
|
7487
CALL
Sportsman's Warehouse
SPWH
$44.9M
| $4.53K | ﹤0.01% |
3,100
-26,100
| -89% | -$56.8K |
|
|
NEXN
7488
Nexxen International
NEXN
$588M
| $4.52K | ﹤0.01% |
+691
| New | +$5.14K |
|
7489
Alpha Tau Medical
DRTS
$1.01B
| $4.51K | ﹤0.01% |
+911
| New | +$3.84K |
|
7490
CALL
MaxCyte
MXCT
$108M
| $4.5K | ﹤0.01% |
2,900
-2,000
| -41% | -$3.19K |
|
7491
CALL
Tucows
TCX
$104M
| $4.48K | ﹤0.01% |
200
-17,600
| -99% | -$357K |
|
7492
Arbe Robotics
ARBE
$73.3M
| $4.47K | ﹤0.01% |
3,793
-107,805
| -97% | -$178K |
|
7493
Genelux
GNLX
$127M
| $4.42K | ﹤0.01% |
+1,014
| New | +$5.48K |
|
7494
PUT
Talos Energy
TALO
$2.38B
| $4.41K | ﹤0.01% |
400
+100
| +33% | +$1.05K |
|
7495
Global X US Infrastructure Development ETF
PAVE
$13.5B
| $4.4K | ﹤0.01% |
+92
| New | +$4.41K |
|
7496
PUT
Quad
QUAD
$479M
| $4.39K | ﹤0.01% |
700
-1,400
| -67% | -$8.23K |
|
7497
PUT
Global X S&P 500 Covered Call ETF
XYLD
$3.19B
| $4.39K | ﹤0.01% |
+100
| New | +$4K |
|
|
BANX
7498
PUT
ArrowMark Financial
BANX
$195M
| $4.36K | ﹤0.01% |
200
| – | – |
|
7499
PUT
First Advantage
FA
$3.69B
| $4.36K | ﹤0.01% |
+300
| New | +$4.23K |
|
7500
PUT
Clarus
CLAR
$125M
| $4.36K | ﹤0.01% |
1,300
-9,000
| -87% | -$30.6K |
|
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.