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 | |
|---|---|---|---|---|---|---|
2751
Interactive Brokers
IBKR
$41.1B
| $773K | ﹤0.01% |
+42,340
| New | +$763K |
|
2752
PUT
MasterCraft Boat Holdings
MCFT
$602M
| $773K | ﹤0.01% |
291
+257
| +756% | +$7.13K |
|
|
MGI
2753
DELISTED
MoneyGram International, Inc. New
MGI
| $773K | ﹤0.01% |
+117,695
| New | +$862K |
|
2754
PUT
AquaBounty Technologies
AQB
$4.63M
| $772K | ﹤0.01% |
58
+25
| +76% | +$4.3K |
|
|
PCH
2755
PUT
DELISTED
PotlatchDeltic
PCH
| $772K | ﹤0.01% |
146
-48
| -25% | -$2.48K |
|
2756
CALL
Axos Financial
AX
$5.45B
| $770K | ﹤0.01% |
164
+9
| +6% | +$405 |
|
2757
ICU Medical
ICUI
$4.04B
| $770K | ﹤0.01% |
3,751
-3,989
| -52% | -$842K |
|
|
RWT
2758
Redwood Trust
RWT
$619M
| $768K | ﹤0.01% |
73,810
+41,187
| +126% | +$396K |
|
|
TRVG
2759
trivago
TRVG
$382M
| $767K | ﹤0.01% |
35,675
+29,497
| +477% | +$498K |
|
|
NVRO
2760
CALL
DELISTED
NEVRO CORP.
NVRO
| $767K | ﹤0.01% |
55
-145
| -73% | -$23.7K |
|
2761
CALL
Ametek
AME
$55.7B
| $766K | ﹤0.01% |
60
-68
| -53% | -$8.21K |
|
|
LPRO
2762
PUT
Open Lending Corp
LPRO
$372M
| $765K | ﹤0.01% |
216
+18
| +9% | +$679 |
|
|
BLCN
2763
CALL
DELISTED
Siren ETF Trust Siren NexGen Economy ETF
BLCN
| $764K | ﹤0.01% |
159
+127
| +397% | +$5.85K |
|
|
TSE
2764
CALL
DELISTED
Trinseo
TSE
| $764K | ﹤0.01% |
120
-77
| -39% | -$4.7K |
|
2765
Asana
ASAN
$1.79B
| $763K | ﹤0.01% |
26,698
-40,000
| -60% | -$1.38M |
|
2766
CALL
Deluxe
DLX
$1.22B
| $763K | ﹤0.01% |
182
-19
| -9% | -$716 |
|
|
BNFT
2767
DELISTED
Benefitfocus, Inc.
BNFT
| $763K | ﹤0.01% |
55,278
+46,581
| +536% | +$670K |
|
2768
PUT
Porch Group
PRCH
$1.39B
| $762K | ﹤0.01% |
+431
| New | +$7.66K |
|
2769
CALL
UGI
UGI
$7.91B
| $762K | ﹤0.01% |
186
+17
| +10% | +$657 |
|
2770
Varonis Systems
VRNS
$5.36B
| $762K | ﹤0.01% |
14,854
-30,080
| -67% | -$1.78M |
|
2771
PUT
Dana Inc
DAN
$2.93B
| $761K | ﹤0.01% |
313
+214
| +216% | +$4.91K |
|
2772
CALL
Jabil
JBL
$32.6B
| $761K | ﹤0.01% |
146
-512
| -78% | -$23.3K |
|
2773
KBR
KBR
$4.67B
| $761K | ﹤0.01% |
19,843
+10,238
| +107% | +$327K |
|
|
WCC
2774
CALL
WESCO International
WCC
$16.5B
| $761K | ﹤0.01% |
88
-58
| -40% | -$4.88K |
|
2775
PUT
Aemetis
AMTX
$109M
| $760K | ﹤0.01% |
310
+304
| +5,067% | +$3.4K |
|
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.