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 | |
|---|---|---|---|---|---|---|
5951
CALL
RadNet
RDNT
$5.02B
| $35.7K | ﹤0.01% |
500
| – | – |
|
5952
CALL
Surgery Partners
SGRY
$2.01B
| $35.5K | ﹤0.01% |
2,300
-11,800
| -84% | -$217K |
|
5953
City Holding Co
CHCO
$2.05B
| $35.5K | ﹤0.01% |
+298
| New | +$36.2K |
|
5954
PUT
Ingevity
NGVT
$2.51B
| $35.5K | ﹤0.01% |
600
+100
| +20% | +$5.43K |
|
5955
REX American Resources
REX
$1.42B
| $35.5K | ﹤0.01% |
+1,097
| New | +$35.7K |
|
5956
CALL
NovaGold Resources
NG
$2.56B
| $35.4K | ﹤0.01% |
3,800
-64,400
| -94% | -$597K |
|
5957
CALL
Pampa Energía
PAM
$4.75B
| $35.4K | ﹤0.01% |
400
-5,000
| -93% | -$403K |
|
5958
Global Net Lease
GNL
$1.84B
| $35.4K | ﹤0.01% |
+4,114
| New | +$33K |
|
|
TDAY
5959
USA Today Co
TDAY
$1.27B
| $35.3K | ﹤0.01% |
6,851
-80,148
| -92% | -$377K |
|
5960
PUT
Suburban Propane Partners
SPH
$1.24B
| $35.2K | ﹤0.01% |
1,900
-7,800
| -80% | -$146K |
|
5961
Standex International
SXI
$3.59B
| $35.2K | ﹤0.01% |
+162
| New | +$37.6K |
|
|
PPLI
5962
PUT
People Inc
PPLI
$3.09B
| $35.2K | ﹤0.01% |
900
-6,900
| -88% | -$242K |
|
|
ZH
5963
Zhihu
ZH
$281M
| $35.2K | ﹤0.01% |
10,728
-7,219
| -40% | -$28.9K |
|
5964
CALL
Knife River
KNF
$4.15B
| $35.2K | ﹤0.01% |
500
+400
| +400% | +$28.1K |
|
5965
Zedge
ZDGE
$38.6M
| $35.2K | ﹤0.01% |
10,724
+10,251
| +2,167% | +$29.7K |
|
|
DSL
5966
DoubleLine Income Solutions Fund
DSL
$1.22B
| $35.2K | ﹤0.01% |
+3,121
| New | +$36.1K |
|
|
FRGE
5967
CALL
DELISTED
Forge Global Holdings
FRGE
| $35.2K | ﹤0.01% |
2,100
+1,500
| +250% | +$50.7K |
|
|
EQLT
5968
PUT
iShares MSCI Emerging Markets Quality Factor ETF
EQLT
$11.9M
| $35.2K | ﹤0.01% |
1,100
+1,000
| +1,000% | +$30.3K |
|
5969
Sturm, Ruger & Co
RGR
$594M
| $35.1K | ﹤0.01% |
+1,076
| New | +$39.9K |
|
5970
CALL
Resideo Technologies
REZI
$5.19B
| $35.1K | ﹤0.01% |
1,000
-14,300
| -93% | -$529K |
|
5971
PUT
Federal Agricultural Mortgage Class A
AGM.A
$1.67B
| $35.1K | ﹤0.01% |
200
-2,500
| -93% | -$315K |
|
5972
YieldMax Innovation Option Income Strategy ETF
OARK
$30.8M
| $35.1K | ﹤0.01% |
966
+921
| +2,047% | +$37.6K |
|
5973
PUT
Mama's Creations
MAMA
$857M
| $35.1K | ﹤0.01% |
2,600
+2,200
| +550% | +$25.3K |
|
|
WCN
5974
CALL
Waste Connections
WCN
$42.2B
| $35.1K | ﹤0.01% |
+200
| New | +$34.6K |
|
5975
PUT
Clean Energy Fuels
CLNE
$427M
| $35.1K | ﹤0.01% |
16,700
+2,300
| +16% | +$5.63K |
|
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.