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 | |
|---|---|---|---|---|---|---|
5301
Duke Energy
DUK
$97.8B
| $73K | ﹤0.01% |
+623
| New | +$76.1K |
|
5302
CALL
Lufax Holding
LU
$1.35B
| $73K | ﹤0.01% |
28,500
-9,500
| -25% | -$28.1K |
|
5303
CALL
Federated Hermes
FHI
$4.55B
| $72.9K | ﹤0.01% |
1,400
| – | – |
|
5304
CALL
International Seaways
INSW
$4.76B
| $72.8K | ﹤0.01% |
1,500
-9,900
| -87% | -$490K |
|
5305
CALL
RELX
RELX
$61.8B
| $72.8K | ﹤0.01% |
1,800
-1,700
| -49% | -$72.6K |
|
|
ZBIO
5306
PUT
Zenas BioPharma
ZBIO
$1.98B
| $72.6K | ﹤0.01% |
+2,000
| New | +$65.8K |
|
|
CVSA
5307
CALL
Covista Inc
CVSA
$4.25B
| $72.4K | ﹤0.01% |
+700
| New | +$80.2K |
|
5308
PUT
Advanced Drainage Systems
WMS
$10.6B
| $72.4K | ﹤0.01% |
500
| – | – |
|
5309
JELD-WEN Holding
JELD
$122M
| $72.4K | ﹤0.01% |
29,414
-24,403
| -45% | -$80.2K |
|
5310
Krystal Biotech
KRYS
$10.1B
| $72.2K | ﹤0.01% |
+293
| New | +$61.7K |
|
5311
iShares Core S&P Mid-Cap ETF
IJH
$122B
| $72.1K | ﹤0.01% |
+1,093
| New | +$71.6K |
|
5312
PUT
National Fuel Gas
NFG
$7.82B
| $72.1K | ﹤0.01% |
900
-800
| -47% | -$65.9K |
|
5313
CALL
DT Midstream
DTM
$14.1B
| $71.8K | ﹤0.01% |
600
-7,600
| -93% | -$873K |
|
5314
RBC Bearings
RBC
$17.4B
| $71.7K | ﹤0.01% |
+160
| New | +$67.8K |
|
|
ZBIO
5315
Zenas BioPharma
ZBIO
$1.98B
| $71.7K | ﹤0.01% |
+1,974
| New | +$64.9K |
|
|
NMG
5316
PUT
Nouveau Monde Graphite
NMG
$428M
| $71.7K | ﹤0.01% |
+28,900
| New | +$84.6K |
|
5317
CALL
Invesco DB Commodity Index Tracking Fund
DBC
$1.69B
| $71.6K | ﹤0.01% |
3,200
-23,000
| -88% | -$523K |
|
5318
CALL
Methanex
MEOH
$4.3B
| $71.5K | ﹤0.01% |
1,800
-11,100
| -86% | -$413K |
|
5319
Vaxcyte
PCVX
$7.81B
| $71.5K | ﹤0.01% |
+1,549
| New | +$69.3K |
|
5320
CALL
Kanzhun
BZ
$7.27B
| $71.3K | ﹤0.01% |
3,500
-22,500
| -87% | -$486K |
|
5321
CALL
Agilysys
AGYS
$2.97B
| $71.3K | ﹤0.01% |
600
+300
| +100% | +$36.1K |
|
5322
CALL
Adtran
ADTN
$689M
| $71.3K | ﹤0.01% |
8,200
-200
| -2% | -$1.74K |
|
5323
CALL
Essential Properties Realty Trust
EPRT
$6.77B
| $71.2K | ﹤0.01% |
2,400
+1,600
| +200% | +$48.8K |
|
5324
CALL
Phillips Edison & Co
PECO
$5.46B
| $71.1K | ﹤0.01% |
2,000
-2,000
| -50% | -$69.4K |
|
5325
CALL
Reynolds Consumer Products
REYN
$5.26B
| $71.1K | ﹤0.01% |
3,100
-1,300
| -30% | -$31.4K |
|
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.