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 | |
|---|---|---|---|---|---|---|
6726
CALL
Mistras Group
MG
$477M
| $38K | ﹤0.01% |
3,900
-181,900
| -98% | -$1.62M |
|
6727
CALL
QuidelOrtho
QDEL
$1.13B
| $38K | ﹤0.01% |
1,300
-1,900
| -59% | -$51.9K |
|
6728
CALL
RadNet
RDNT
$4.98B
| $38K | ﹤0.01% |
+500
| New | +$32.5K |
|
6729
Invesco S&P SmallCap 600 Pure Value ETF
RZV
$291M
| $38K | ﹤0.01% |
+328
| New | +$37.2K |
|
6730
Tootsie Roll Industries
TR
$2.97B
| $38K | ﹤0.01% |
939
+318
| +51% | +$12K |
|
6731
CALL
Toro Company
TTC
$8.79B
| $38K | ﹤0.01% |
500
-100
| -17% | -$7.67K |
|
|
RAPP
6732
CALL
Rapport Therapeutics
RAPP
$1.96B
| $38K | ﹤0.01% |
+1,300
| New | +$23.2K |
|
|
AAMI
6733
PUT
Acadian Asset Management
AAMI
$2.88B
| $38K | ﹤0.01% |
+800
| New | +$35.7K |
|
|
NTSK
6734
PUT
Netskope Inc
NTSK
$4.83B
| $38K | ﹤0.01% |
+1,700
| New | +$40.4K |
|
6735
CALL
Alarm.com
ALRM
$2.75B
| $37K | ﹤0.01% |
700
+100
| +17% | +$5.58K |
|
6736
Grupo Aeroportuario del Sureste
ASR
$8.16B
| $37K | ﹤0.01% |
+117
| New | +$37.7K |
|
|
BLD
6737
DELISTED
TopBuild
BLD
| $37K | ﹤0.01% |
97
+50
| +106% | +$20K |
|
6738
PUT
Clean Energy Fuels
CLNE
$416M
| $37K | ﹤0.01% |
14,400
+3,000
| +26% | +$7.02K |
|
6739
CPS Technologies
CPSH
$67.6M
| $37K | ﹤0.01% |
10,633
-1,809
| -15% | -$5.62K |
|
6740
PUT
China Yuchai International
CYD
$1.69B
| $37K | ﹤0.01% |
900
-10,400
| -92% | -$314K |
|
6741
CALL
Endava
DAVA
$165M
| $37K | ﹤0.01% |
4,100
+300
| +8% | +$3.74K |
|
6742
ProShares Ultra Dow30
DDM
$524M
| $37K | ﹤0.01% |
694
+282
| +68% | +$14.4K |
|
6743
Dream Finders Homes
DFH
$1.41B
| $37K | ﹤0.01% |
1,454
-1,477
| -50% | -$40.6K |
|
6744
PUT
Evolution Petroleum
EPM
$133M
| $37K | ﹤0.01% |
7,700
+7,400
| +2,467% | +$36.9K |
|
6745
CALL
Gates Industrial Corporation Ltd.
GTES
$6.31B
| $37K | ﹤0.01% |
1,500
-11,600
| -89% | -$288K |
|
6746
GraniteShares HIPS US High Income ETF
HIPS
$110M
| $37K | ﹤0.01% |
3,145
+285
| +10% | +$3.48K |
|
6747
CALL
Hancock Whitney
HWC
$6.19B
| $37K | ﹤0.01% |
600
+100
| +20% | +$6.13K |
|
6748
Lithia Motors
LAD
$9.75B
| $37K | ﹤0.01% |
120
-1,914
| -94% | -$617K |
|
6749
CALL
Lifestance Health
LFST
$4.15B
| $37K | ﹤0.01% |
6,800
-44,900
| -87% | -$220K |
|
6750
CALL
LiveOne
LVO
$59.8M
| $37K | ﹤0.01% |
+9,200
| New | +$57K |
|
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.