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 | Miscellaneous | 97.22% |
| 2 | Technology | 0.66% |
| 3 | Consumer Discretionary | 0.49% |
| 4 | Healthcare | 0.33% |
| 5 | Financials | 0.3% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
551
PUT
Diamondback Energy
FANG
$55.8B
| $7.91M | 0.01% |
1,077
+243
| +29% | +$16.6K |
|
552
PUT
Ferrari
RACE
$72.1B
| $7.91M | 0.01% |
378
-135
| -26% | -$27.6K |
|
553
CALL
ArcelorMittal
MT
$59.4B
| $7.88M | 0.01% |
2,701
-1,782
| -40% | -$43.6K |
|
554
PUT
Proshares UltraShort Technology
REW
$3M
| $7.84M | 0.01% |
402
-875
| -69% | -$186K |
|
555
CALL
Allstate
ALL
$65.6B
| $7.84M | 0.01% |
682
-333
| -33% | -$36.7K |
|
556
PUT
GDS Holdings
GDS
$6.28B
| $7.83M | 0.01% |
966
+183
| +23% | +$18.2K |
|
557
CALL
MGM Resorts International
MGM
$10.4B
| $7.83M | 0.01% |
+2,061
| New | +$71.9K |
|
558
CALL
Mondelez International
MDLZ
$78.2B
| $7.83M | 0.01% |
1,337
+131
| +11% | +$7.39K |
|
559
PUT
Pultegroup
PHM
$23.7B
| $7.77M | 0.01% |
1,481
+96
| +7% | +$4.48K |
|
560
CALL
Lennar Class B
LEN.B
$19.8B
| $7.74M | 0.01% |
805
-857
| -52% | -$57.1K |
|
561
CALL
Amplify Junior Silver Miners ETF
SILJ
$4.16B
| $7.74M | 0.01% |
7,301
+3,902
| +115% | +$60.1K |
|
562
PUT
Crocs
CROX
$5.63B
| $7.73M | 0.01% |
961
+782
| +437% | +$59.6K |
|
|
ALXN
563
PUT
DELISTED
Alexion Pharmaceuticals
ALXN
| $7.72M | 0.01% |
505
-258
| -34% | -$39.9K |
|
564
CALL
Linde
LIN
$220B
| $7.7M | 0.01% |
275
-238
| -46% | -$61.7K |
|
565
PUT
Molson Coors Class B
TAP
$7.55B
| $7.66M | 0.01% |
1,498
+979
| +189% | +$47.6K |
|
566
CALL
Stanley Black & Decker
SWK
$14.7B
| $7.65M | 0.01% |
383
+267
| +230% | +$48.4K |
|
567
PUT
Phillips 66
PSX
$102B
| $7.62M | 0.01% |
935
-786
| -46% | -$61.7K |
|
568
CALL
Kroger
KR
$35.9B
| $7.62M | 0.01% |
2,116
-1,133
| -35% | -$38.7K |
|
|
SFIX
569
CALL
Stitch Fix
SFIX
$407M
| $7.61M | 0.01% |
+1,536
| New | +$108K |
|
570
PUT
United Rentals
URI
$62.9B
| $7.61M | 0.01% |
231
-695
| -75% | -$197K |
|
571
PUT
Invesco Aerospace & Defense ETF
PPA
$7.91B
| $7.6M | 0.01% |
876
-687
| -44% | -$47.5K |
|
572
CALL
Duke Energy
DUK
$93.7B
| $7.57M | 0.01% |
784
-478
| -38% | -$43.6K |
|
573
CALL
FirstEnergy
FE
$27.1B
| $7.49M | 0.01% |
2,158
-853
| -28% | -$27.9K |
|
574
PUT
American Water Works
AWK
$28B
| $7.48M | 0.01% |
499
+262
| +111% | +$39.7K |
|
|
APHA
575
CALL
DELISTED
Aphria Inc. Common Shares
APHA
| $7.44M | 0.01% |
4,050
+2,161
| +114% | +$35K |
|
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's Q1 2021 filing shows 2,255 new, 3,360 increased, 3,150 reduced and 1,707 closed positions. Its largest new stake was Pfizer: 464,628 shares worth $16.8M. The largest sale was Amazon, an estimated $66M.
By sector, the portfolio is most concentrated in Miscellaneous at 97% of assets, down from 98% a quarter earlier, followed by Technology and Consumer Discretionary.
- 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 2,255 new positions and closed 1,707 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.