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 |
Microsoft
MSFT
|
+$234M |
| 2 |
iShares Russell 2000 ETF
IWM
|
+$97.5M |
| 3 |
Amazon
AMZN
|
+$96.8M |
| 4 |
iShares Bitcoin Trust
IBIT
|
+$80.6M |
| 5 |
Pinduoduo
PDD
|
+$54.9M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
iShares 20+ Year Treasury Bond ETF
TLT
|
+$129M |
| 2 |
Alphabet (Google) Class A
GOOGL
|
+$92.9M |
| 3 |
Broadcom
AVGO
|
+$82.9M |
| 4 |
Alphabet (Google) Class C
GOOG
|
+$68.4M |
| 5 |
Meta Platforms (Facebook)
META
|
+$59.2M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 0.79% |
| 2 | Consumer Discretionary | 0.3% |
| 3 | Healthcare | 0.25% |
| 4 | Financials | 0.17% |
| 5 | Industrials | 0.09% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
6001
CALL
KBR
KBR
$4.36B
| $80K | ﹤0.01% |
1,700
-4,000
| -70% | -$194K |
|
6002
Orthofix Medical
OFIX
$477M
| $80K | ﹤0.01% |
5,502
+4,882
| +787% | +$64.1K |
|
6003
CALL
Sportsman's Warehouse
SPWH
$45.3M
| $80K | ﹤0.01% |
29,200
-3,600
| -11% | -$11.5K |
|
6004
Viavi Solutions
VIAV
$8.65B
| $80K | ﹤0.01% |
6,370
-66,099
| -91% | -$727K |
|
|
GSRT
6005
CALL
DELISTED
GSR III Acquisition Corp
GSRT
| $80K | ﹤0.01% |
+104,000
| New | +$1.1M |
|
|
CEPO
6006
CALL
Cantor Equity Partners I
CEPO
$272M
| $80K | ﹤0.01% |
+7,700
| New | +$85.2K |
|
6007
CALL
Anterix
ATEX
$1.82B
| $79K | ﹤0.01% |
3,700
-2,300
| -38% | -$51.6K |
|
|
BCYC
6008
CALL
Bicycle Therapeutics
BCYC
$280M
| $79K | ﹤0.01% |
10,300
+8,800
| +587% | +$66.4K |
|
6009
CALL
Eve Holding
EVEX
$812M
| $79K | ﹤0.01% |
+20,900
| New | +$111K |
|
6010
Interparfums
IPAR
$4.02B
| $79K | ﹤0.01% |
810
+572
| +240% | +$67.4K |
|
6011
PUT
LoveSac
LOVE
$236M
| $79K | ﹤0.01% |
4,700
+2,700
| +135% | +$50.2K |
|
6012
PUT
ManpowerGroup
MAN
$2.41B
| $79K | ﹤0.01% |
2,100
+400
| +24% | +$16.5K |
|
6013
Direxion Daily MSCI Mexico Bull 3X ETF
MEXX
$20M
| $79K | ﹤0.01% |
+3,360
| New | +$62.7K |
|
6014
CALL
National Health Investors
NHI
$3.69B
| $79K | ﹤0.01% |
1,000
+900
| +900% | +$67.3K |
|
6015
CALL
Qualys
QLYS
$4.99B
| $79K | ﹤0.01% |
+600
| New | +$81.4K |
|
6016
PUT
SELLAS Life Sciences
SLS
$2.02B
| $79K | ﹤0.01% |
49,400
+1,100
| +2% | +$1.96K |
|
6017
CALL
Westlake Chemical Partners
WLKP
$766M
| $79K | ﹤0.01% |
3,800
-3,700
| -49% | -$81.1K |
|
6018
CALL
Adtran
ADTN
$682M
| $78K | ﹤0.01% |
8,400
+7,700
| +1,100% | +$71.7K |
|
6019
Cullinan Oncology
CGEM
$1.08B
| $78K | ﹤0.01% |
13,285
-6,272
| -32% | -$45.9K |
|
6020
CALL
CuriosityStream
CURI
$143M
| $78K | ﹤0.01% |
14,800
-4,100
| -22% | -$18.9K |
|
6021
PUT
Cousins Properties
CUZ
$5.25B
| $78K | ﹤0.01% |
2,700
+100
| +4% | +$2.84K |
|
6022
Elbit Systems
ESLT
$36.8B
| $78K | ﹤0.01% |
154
-62
| -29% | -$29.1K |
|
6023
PUT
The Greenbrier Companies
GBX
$1.52B
| $78K | ﹤0.01% |
1,700
+1,200
| +240% | +$57.2K |
|
6024
PUT
Greystone Housing Impact Investors LP
GHI
$124M
| $78K | ﹤0.01% |
7,600
+3,000
| +65% | +$32.7K |
|
6025
CALL
Goldman Sachs Innovate Equity ETF
GINN
$204M
| $78K | ﹤0.01% |
1,500
+1,300
| +650% | +$90.9K |
|
Similar funds
Simplex Trading's Q3 2025 Portfolio in Review
As of Q3 2025, Simplex Trading held 10,358 positions worth $195B, up 12% from $175B the previous quarter. Its ten largest holdings account for 46% of the portfolio.
Simplex Trading's Q3 2025 filing shows 1,743 new, 3,828 increased, 3,250 reduced and 1,308 closed positions. Its largest new stake was Microsoft: 458,309 shares worth $237M. The largest sale was iShares 20+ Year Treasury Bond ETF, an estimated $129M.
By sector, the portfolio is most concentrated in Technology at 0.79% of assets, up from 0.74% a quarter earlier, followed by Consumer Discretionary and Healthcare.
- Simplex Trading's largest Q3 2025 buy was Microsoft: 458,309 shares worth $237M.
- Simplex Trading added most to iShares Russell 2000 ETF in Q3 2025, an estimated $97.5M increase.
- Simplex Trading's biggest Q3 2025 reduction was Alphabet (Google) Class A, cutting an estimated $92.9M.
- Simplex Trading fully exited iShares 20+ Year Treasury Bond ETF in Q3 2025, selling an estimated $129M.
- Simplex Trading's ten largest holdings make up 46% of its $195B portfolio in Q3 2025.
- Simplex Trading opened 1,743 new positions and closed 1,308 in Q3 2025.
- Simplex Trading's portfolio value rose 12% quarter-over-quarter to $195B.
Based on Simplex Trading's 13F filing for Q3 2025, filed 12 Nov 2025.