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 | |
|---|---|---|---|---|---|---|
676
PUT
Capri Holdings
CPRI
$1.77B
| $6.14M | 0.01% |
1,205
-1,754
| -59% | -$82.6K |
|
677
CALL
Opendoor
OPEN
$3.69B
| $6.11M | 0.01% |
2,980
+849
| +40% | +$22.4K |
|
678
PUT
ArcelorMittal
MT
$50.2B
| $6.1M | 0.01% |
2,090
-104
| -5% | -$2.54K |
|
679
PUT
Agilent Technologies
A
$39B
| $6.09M | 0.01% |
479
+77
| +19% | +$9.52K |
|
680
CALL
Cummins
CMI
$91.2B
| $6.09M | 0.01% |
235
+49
| +26% | +$12.2K |
|
681
PUT
Huntington Ingalls Industries
HII
$11.4B
| $6.07M | 0.01% |
295
+192
| +186% | +$34.4K |
|
682
CALL
PTC
PTC
$13.5B
| $6.07M | 0.01% |
441
-80
| -15% | -$10.7K |
|
|
KL
683
PUT
DELISTED
Kirkland Lake Gold Ltd Ordinary
KL
| $6.07M | 0.01% |
1,796
+548
| +44% | +$20.3K |
|
684
CALL
State Street SPDR Portfolio Europe ETF
SPEU
$712M
| $6.06M | 0.01% |
1,320
+987
| +296% | +$38.3K |
|
685
PUT
L3Harris
LHX
$56.3B
| $6.06M | 0.01% |
299
-257
| -46% | -$48.2K |
|
686
CALL
Air Products & Chemicals
APD
$66B
| $6.05M | 0.01% |
215
-35
| -14% | -$9.52K |
|
687
CALL
Magnite
MGNI
$2.59B
| $6.04M | 0.01% |
1,451
+249
| +21% | +$10.8K |
|
688
PUT
Sabre
SABR
$660M
| $6.03M | 0.01% |
4,071
+112
| +3% | +$1.52K |
|
689
Intuitive Surgical
ISRG
$121B
| $6.02M | 0.01% |
24,456
+14,880
| +155% | +$3.74M |
|
690
CALL
Magna International
MGA
$18B
| $6.02M | 0.01% |
684
-215
| -24% | -$17.5K |
|
691
CALL
Reliance Steel & Aluminium
RS
$20.4B
| $6.01M | 0.01% |
395
-5
| -1% | -$673 |
|
692
PUT
VF Corp
VFC
$6.61B
| $6.01M | 0.01% |
752
-366
| -33% | -$29.7K |
|
693
PUT
Oneok
OKE
$60.3B
| $5.98M | 0.01% |
1,181
+169
| +17% | +$7.68K |
|
694
PUT
Innovative Industrial Properties
IIPR
$1.79B
| $5.98M | 0.01% |
332
+249
| +300% | +$47.7K |
|
695
PUT
Teva Pharmaceuticals
TEVA
$36B
| $5.98M | 0.01% |
5,180
-944
| -15% | -$10.8K |
|
696
CALL
Corsair Gaming
CRSR
$1.04B
| $5.95M | 0.01% |
1,786
+1,366
| +325% | +$50.8K |
|
697
ASML
ASML
$677B
| $5.93M | 0.01% |
+9,613
| New | +$5.33M |
|
698
CALL
Trip.com Group
TCOM
$27.5B
| $5.93M | 0.01% |
1,497
-1,092
| -42% | -$40.4K |
|
699
American Tower
AMT
$78.5B
| $5.92M | 0.01% |
24,779
+7,887
| +47% | +$1.76M |
|
700
PUT
Halliburton
HAL
$27.9B
| $5.92M | 0.01% |
2,760
-1,710
| -38% | -$35.8K |
|
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.