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 |
iShares Russell 2000 ETF
IWM
|
+$67.5M |
| 2 |
Palantir
PLTR
|
+$64.7M |
| 3 |
PARA
Paramount Global Class B
PARA
|
+$31.5M |
| 4 |
State Street SPDR Dow Jones Industrial Average ETF Trust
DIA
|
+$30.7M |
| 5 |
Carnival Corporation Ltd
CCL
|
+$25.7M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
Amazon
AMZN
|
+$66M |
| 2 |
Tesla
TSLA
|
+$53.7M |
| 3 |
Alphabet (Google) Class C
GOOG
|
+$38.1M |
| 4 |
Invesco QQQ Trust
QQQ
|
+$37.6M |
| 5 |
AutoZone
AZO
|
+$28.5M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 0.65% |
| 2 | Consumer Discretionary | 0.49% |
| 3 | Healthcare | 0.32% |
| 4 | Financials | 0.3% |
| 5 | Industrials | 0.29% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
1001
PUT
JetBlue
JBLU
$1.96B
| $3.99M | 0.01% |
1,960
+751
| +62% | +$13K |
|
1002
PUT
ACM Research
ACMR
$5.83B
| $3.97M | 0.01% |
1,476
+1,344
| +1,018% | +$44.4K |
|
|
ANSS
1003
PUT
DELISTED
Ansys
ANSS
| $3.97M | 0.01% |
117
+14
| +14% | +$4.97K |
|
1004
CALL
Clover Health Investments
CLOV
$2.28B
| $3.97M | 0.01% |
5,253
+1,760
| +50% | +$19.9K |
|
1005
PUT
Renaissance IPO ETF
IPO
$154M
| $3.97M | 0.01% |
638
+534
| +513% | +$36.1K |
|
1006
PUT
Blink Charging
BLNK
$75.2M
| $3.97M | 0.01% |
965
-1,303
| -57% | -$56.8K |
|
1007
CALL
O'Reilly Automotive
ORLY
$72.4B
| $3.96M | 0.01% |
1,170
-975
| -45% | -$30.2K |
|
1008
PUT
Fluor
FLR
$7.29B
| $3.95M | 0.01% |
1,711
+940
| +122% | +$18.3K |
|
1009
CALL
Planet Fitness
PLNT
$4.23B
| $3.92M | 0.01% |
507
-85
| -14% | -$6.75K |
|
|
AGNT
1010
CALL
AGNT Inc
AGNT
$664M
| $3.92M | 0.01% |
860
-364
| -30% | -$19.4K |
|
1011
PUT
GFL Environmental
GFL
$14.3B
| $3.92M | 0.01% |
1,121
+1,036
| +1,219% | +$32K |
|
1012
PUT
Steel Dynamics
STLD
$35.6B
| $3.91M | 0.01% |
771
-55
| -7% | -$2.32K |
|
|
SPR
1013
PUT
DELISTED
Spirit AeroSystems
SPR
| $3.91M | 0.01% |
803
-669
| -45% | -$28.6K |
|
1014
Thermo Fisher Scientific
TMO
$211B
| $3.9M | 0.01% |
+8,537
| New | +$4.07M |
|
1015
CALL
BJs Wholesale Club
BJ
$11.9B
| $3.89M | 0.01% |
867
+25
| +3% | +$1.05K |
|
|
MCFE
1016
PUT
DELISTED
McAfee Corp. Class A Common Stock
MCFE
| $3.89M | 0.01% |
1,710
+1,673
| +4,522% | +$34.8K |
|
1017
PUT
BioNTech
BNTX
$22.6B
| $3.89M | 0.01% |
356
-164
| -32% | -$17.4K |
|
1018
Vertex Pharmaceuticals
VRTX
$121B
| $3.88M | 0.01% |
18,054
-8,094
| -31% | -$1.78M |
|
1019
PUT
Verisk Analytics
VRSK
$26.4B
| $3.87M | 0.01% |
219
-15
| -6% | -$2.75K |
|
1020
PUT
JB Hunt Transport Services
JBHT
$27.1B
| $3.87M | 0.01% |
230
+152
| +195% | +$22.9K |
|
1021
PUT
KLA
KLAC
$275B
| $3.87M | 0.01% |
1,170
-1,090
| -48% | -$32.8K |
|
1022
PUT
Martin Marietta Materials
MLM
$33.6B
| $3.86M | 0.01% |
115
-179
| -61% | -$57.2K |
|
1023
PUT
InMode
INMD
$872M
| $3.86M | 0.01% |
1,066
+244
| +30% | +$7.92K |
|
|
WLL
1024
PUT
DELISTED
Whiting Petroleum Corporation
WLL
| $3.85M | 0.01% |
1,489
-1,426
| -49% | -$42.6K |
|
|
ML
1025
PUT
DELISTED
MoneyLion Inc.
ML
| $3.84M | 0.01% |
+129
| New | +$43.1K |
|
Similar funds
Simplex Trading's Q1 2021 Portfolio in Review
As of Q1 2021, Simplex Trading held 10,706 positions worth $55.7B, down 28% from $77.2B the previous quarter. Its ten largest holdings account for 43% of the portfolio.
Simplex Trading withdrew a net $23.5B in Q1 2021, closing 1,706 positions and reducing 3,151 holdings. Its most notable exit was Alphabet (Google) Class C, an estimated $38.1M position sold in full.
By sector, the portfolio is most concentrated in Technology at 0.65% of assets, up from 0.37% a quarter earlier, followed by Consumer Discretionary and Healthcare.
Against the trend, Simplex Trading opened a new position in Pfizer worth $16.8M.
- Simplex Trading's largest Q1 2021 buy was Pfizer: 464,628 shares worth $16.8M.
- Simplex Trading added most to iShares Russell 2000 ETF in Q1 2021, an estimated $67.5M increase.
- Simplex Trading's biggest Q1 2021 reduction was Amazon, cutting an estimated $66M.
- Simplex Trading fully exited Alphabet (Google) Class C in Q1 2021, selling an estimated $38.1M.
- Simplex Trading's ten largest holdings make up 43% of its $55.7B portfolio in Q1 2021.
- Simplex Trading opened 2,258 new positions and closed 1,706 in Q1 2021.
- Simplex Trading's portfolio value fell 28% quarter-over-quarter to $55.7B.
Based on Simplex Trading's 13F filing for Q1 2021, filed 26 Apr 2021.