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 | Miscellaneous | 98.27% |
| 2 | Technology | 0.59% |
| 3 | Consumer Discretionary | 0.21% |
| 4 | Healthcare | 0.2% |
| 5 | Industrials | 0.18% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
826
PUT
Honeywell
HON
$66.4B
| $10.4M | 0.01% |
116,100
+21,565
| +23% | +$4.22M |
|
827
PUT
Kohl's
KSS
$2.2B
| $10.4M | 0.01% |
508,900
-192,300
| -27% | -$3.6M |
|
828
PUT
Jabil
JBL
$32.5B
| $10.4M | 0.01% |
45,500
-3,700
| -8% | -$789K |
|
829
CALL
Williams Companies
WMB
$90.7B
| $10.3M | 0.01% |
171,600
-48,400
| -22% | -$2.93M |
|
830
CALL
Biogen
BIIB
$32.6B
| $10.3M | 0.01% |
58,500
-14,500
| -20% | -$2.37M |
|
831
CALL
CarMax
KMX
$8.98B
| $10.3M | 0.01% |
265,900
-17,900
| -6% | -$716K |
|
832
PUT
Kinross Gold
KGC
$36.6B
| $10.3M | 0.01% |
364,400
-12,800
| -3% | -$333K |
|
833
PUT
WEC Energy
WEC
$34.5B
| $10.3M | 0.01% |
97,300
+72,100
| +286% | +$7.98M |
|
834
PUT
Medtronic
MDT
$120B
| $10.3M | 0.01% |
106,800
+17,400
| +19% | +$1.69M |
|
835
PUT
JetBlue
JBLU
$1.75B
| $10.3M | 0.01% |
2,254,100
+95,700
| +4% | +$436K |
|
836
CALL
Nokia
NOK
$56.2B
| $10.2M | 0.01% |
1,582,700
+1,086,300
| +219% | +$6.73M |
|
837
CALL
Bitwise Bitcoin ETF
BITB
$2.95B
| $10.2M | 0.01% |
215,100
+82,400
| +62% | +$4.48M |
|
838
CALL
Vodafone
VOD
$39.1B
| $10.2M | 0.01% |
773,600
-249,700
| -24% | -$3.02M |
|
839
CALL
BHP
BHP
$230B
| $10.2M | 0.01% |
169,200
+61,500
| +57% | +$3.49M |
|
840
PUT
Archer Daniels Midland
ADM
$40.8B
| $10.2M | 0.01% |
177,500
-25,600
| -13% | -$1.53M |
|
841
CALL
Golar LNG
GLNG
$5.32B
| $10.2M | 0.01% |
274,000
+39,900
| +17% | +$1.53M |
|
842
PUT
Centrus Energy
LEU
$3.47B
| $10.1M | 0.01% |
41,800
-19,300
| -32% | -$5.83M |
|
|
MPT
843
PUT
Medical Properties Trust
MPT
$2.39B
| $10.1M | 0.01% |
2,027,700
-963,500
| -32% | -$5.02M |
|
844
PUT
Etsy
ETSY
$7.02B
| $10.1M | 0.01% |
182,200
-421,700
| -70% | -$25.7M |
|
845
CALL
Maplebear
CART
$11.8B
| $10.1M | 0.01% |
224,500
-61,000
| -21% | -$2.5M |
|
846
D-Wave Quantum Inc
QBTS
$6.18B
| $10.1M | 0.01% |
386,080
-63,521
| -14% | -$1.85M |
|
847
iShares Bitcoin Trust
IBIT
$62.2B
| $10.1M | 0.01% |
202,920
-1,325,695
| -87% | -$75.3M |
|
848
ProShares UltraPro Short QQQ
SQQQ
$2.09B
| $10M | 0.01% |
146,477
+86,179
| +143% | +$6.09M |
|
849
CALL
APA Corp
APA
$15B
| $10M | 0.01% |
409,200
+18,900
| +5% | +$457K |
|
850
PUT
American International
AIG
$39.8B
| $10M | 0.01% |
116,900
+29,100
| +33% | +$2.33M |
|
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's Q4 2025 filing shows 1,476 new, 2,599 increased, 4,088 reduced and 2,184 closed positions. Its largest new stake was Western Digital: 341,762 shares worth $58.9M. The largest sale was NVIDIA, an estimated $262M.
By sector, the portfolio is most concentrated in Miscellaneous at 98% of assets, up from 98% a quarter earlier, followed by Technology and Consumer Discretionary.
- 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.