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 | |
|---|---|---|---|---|---|---|
7126
CALL
DiaMedica Therapeutics
DMAC
$358M
| $25K | ﹤0.01% |
3,700
+2,800
| +311% | +$15.2K |
|
7127
PUT
Dorchester Minerals
DMLP
$1.3B
| $25K | ﹤0.01% |
1,000
+700
| +233% | +$18.3K |
|
7128
iShares MSCI Switzerland ETF
EWL
$2.19B
| $25K | ﹤0.01% |
+460
| New | +$25.2K |
|
7129
CALL
Fate Therapeutics
FATE
$270M
| $25K | ﹤0.01% |
20,400
+16,100
| +374% | +$17.4K |
|
7130
4D Molecular Therapeutics
FDMT
$515M
| $25K | ﹤0.01% |
2,925
-6,436
| -69% | -$38.5K |
|
7131
CALL
Fossil Group
FOSL
$262M
| $25K | ﹤0.01% |
10,000
+9,000
| +900% | +$21.3K |
|
7132
PUT
Fortrea Holdings
FTRE
$1.96B
| $25K | ﹤0.01% |
3,000
+2,400
| +400% | +$18.4K |
|
7133
PUT
Invesco CurrencyShares British Pound Sterling Trust
FXB
$76.7M
| $25K | ﹤0.01% |
+200
| New | +$25.9K |
|
7134
PUT
Gentex
GNTX
$5.12B
| $25K | ﹤0.01% |
900
+500
| +125% | +$13.3K |
|
7135
PUT
Hexcel
HXL
$8.3B
| $25K | ﹤0.01% |
400
+300
| +300% | +$18.4K |
|
7136
PUT
Immersion
IMMR
$254M
| $25K | ﹤0.01% |
3,500
-142,700
| -98% | -$1.03M |
|
7137
INmune Bio
INMB
$45.5M
| $25K | ﹤0.01% |
12,508
-57,835
| -82% | -$132K |
|
7138
iShares Micro-Cap ETF
IWC
$1.45B
| $25K | ﹤0.01% |
+174
| New | +$24.1K |
|
7139
Lifecore Biomedical
LFCR
$165M
| $25K | ﹤0.01% |
+3,397
| New | +$25.7K |
|
7140
CALL
Luxfer Holdings
LXFR
$456M
| $25K | ﹤0.01% |
1,800
+1,700
| +1,700% | +$21.8K |
|
7141
PUT
Monro
MNRO
$537M
| $25K | ﹤0.01% |
1,400
-8,200
| -85% | -$135K |
|
7142
Navient
NAVI
$822M
| $25K | ﹤0.01% |
+1,920
| New | +$26.1K |
|
7143
PUT
Ocugen
OCGN
$420M
| $25K | ﹤0.01% |
15,900
-1,100
| -6% | -$1.22K |
|
7144
Invesco Golden Dragon China ETF
PGJ
$94.7M
| $25K | ﹤0.01% |
+782
| New | +$23.9K |
|
7145
Palomar
PLMR
$3.79B
| $25K | ﹤0.01% |
220
-60
| -21% | -$7.61K |
|
|
PLYM
7146
DELISTED
Plymouth Industrial REIT
PLYM
| $25K | ﹤0.01% |
+1,143
| New | +$21K |
|
7147
PUT
Construction Partners
ROAD
$6.03B
| $25K | ﹤0.01% |
+200
| New | +$22.8K |
|
7148
CALL
SiteOne Landscape Supply
SITE
$4.58B
| $25K | ﹤0.01% |
200
-1,800
| -90% | -$244K |
|
7149
PUT
Solid Biosciences
SLDB
$785M
| $25K | ﹤0.01% |
4,200
+1,300
| +45% | +$7.6K |
|
7150
CALL
Smith & Nephew
SNN
$13.7B
| $25K | ﹤0.01% |
+700
| New | +$24.2K |
|
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.