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 | |
|---|---|---|---|---|---|---|
|
LGMK
6076
DELISTED
LogicMark
LGMK
| $78K | ﹤0.01% |
11
+2
| +22% | +$15.8K |
|
6077
Mitsubishi UFJ Financial
MUFG
$253B
| $78K | ﹤0.01% |
14,582
+8,492
| +139% | +$43.8K |
|
|
NGD
6078
DELISTED
New Gold Inc
NGD
| $78K | ﹤0.01% |
50,755
-41,686
| -45% | -$75.4K |
|
6079
PUT
Natural Health Trends
NHTC
$14.7M
| $78K | ﹤0.01% |
116
+28
| +32% | +$179 |
|
6080
Nelnet
NNI
$4.88B
| $78K | ﹤0.01% |
1,084
-226
| -17% | -$16.4K |
|
6081
Progress Software
PRGS
$1.66B
| $78K | ﹤0.01% |
1,790
-4,404
| -71% | -$193K |
|
6082
Primoris Services
PRIM
$4.58B
| $78K | ﹤0.01% |
2,371
+2,184
| +1,168% | +$71.9K |
|
|
TRTX
6083
CALL
TPG RE Finance Trust
TRTX
$612M
| $78K | ﹤0.01% |
70
+24
| +52% | +$263 |
|
6084
PUT
Mammoth Energy Services
TUSK
$128M
| $78K | ﹤0.01% |
148
+22
| +17% | +$111 |
|
|
6085
AutoZone
AZO
$49.2B
| $77K | ﹤0.01% |
55
-23,001
| -100% | -$28.5M |
|
6086
PUT
Bally's
BALY
$682M
| $77K | ﹤0.01% |
12
-75
| -86% | -$4.45K |
|
6087
BJs Wholesale Club
BJ
$12.5B
| $77K | ﹤0.01% |
1,738
+1,056
| +155% | +$44.3K |
|
6088
PUT
Corbus Pharmaceuticals
CRBP
$166M
| $77K | ﹤0.01% |
13
+4
| +44% | +$263 |
|
6089
Commault Systems
CVLT
$4.88B
| $77K | ﹤0.01% |
1,207
-4,077
| -77% | -$259K |
|
6090
Geospace Technologies
GEOS
$94.6M
| $77K | ﹤0.01% |
8,506
+1,629
| +24% | +$15.7K |
|
6091
CALL
Gladstone Capital
GLAD
$422M
| $77K | ﹤0.01% |
39
+31
| +388% | +$597 |
|
6092
PUT
Grocery Outlet
GO
$909M
| $77K | ﹤0.01% |
+21
| New | +$816 |
|
6093
Immunic
IMUX
$190M
| $77K | ﹤0.01% |
+483
| New | +$81.9K |
|
6094
PUT
Mustang Bio
MBIO
$4.32M
| – | – |
-1
| Closed | -$2.97K |
|
6095
PUT
Marcus Corp
MCS
$897M
| $77K | ﹤0.01% |
39
+25
| +179% | +$462 |
|
6096
PUT
Marker Therapeutics
MRKR
$18.8M
| $77K | ﹤0.01% |
+35
| New | +$801 |
|
|
MODN
6097
CALL
DELISTED
MODEL N, INC.
MODN
| $77K | ﹤0.01% |
22
-30
| -58% | -$1.15K |
|
|
COWN
6098
PUT
DELISTED
Cowen Inc. Class A Common Stock
COWN
| $77K | ﹤0.01% |
22
+7
| +47% | +$225 |
|
|
GRA
6099
PUT
DELISTED
W.R. Grace & Co.
GRA
| $77K | ﹤0.01% |
13
-124
| -91% | -$7.4K |
|
|
CKH
6100
PUT
DELISTED
Seacor Holdings Inc.
CKH
| $77K | ﹤0.01% |
+19
| New | +$795 |
|
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.