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 | |
|---|---|---|---|---|---|---|
6401
PUT
Rentokil
RTO
$14.8B
| $53K | ﹤0.01% |
2,100
+1,900
| +950% | +$46.3K |
|
|
HTO
6402
PUT
H2O America
HTO
$2.67B
| $53K | ﹤0.01% |
1,100
+800
| +267% | +$39.9K |
|
6403
CALL
SkinHealth Systems
SKIN
$83.4M
| $53K | ﹤0.01% |
26,900
-116,000
| -81% | -$235K |
|
|
FIRY
6404
CALL
Firy Inc
FIRY
$154M
| $53K | ﹤0.01% |
6,700
+800
| +14% | +$6.15K |
|
6405
PUT
SS&C Technologies
SSNC
$18.9B
| $53K | ﹤0.01% |
600
+500
| +500% | +$43.3K |
|
6406
PUT
W.R. Berkley
WRB
$28.1B
| $53K | ﹤0.01% |
700
-3,100
| -82% | -$221K |
|
|
MSTZ
6407
T-Rex 2X Inverse MSTR Daily Target ETF
MSTZ
$105M
| $53K | ﹤0.01% |
10,213
-94,945
| -90% | -$426K |
|
6408
PUT
A10 Networks
ATEN
$2.07B
| $52K | ﹤0.01% |
2,900
-700
| -19% | -$12.7K |
|
6409
PUT
Avista
AVA
$3.43B
| $52K | ﹤0.01% |
1,400
| – | – |
|
6410
CALL
Barings BDC
BBDC
$869M
| $52K | ﹤0.01% |
6,000
-11,200
| -65% | -$105K |
|
6411
Emergent Biosolutions
EBS
$379M
| $52K | ﹤0.01% |
+5,932
| New | +$46.1K |
|
6412
CALL
Euronet Worldwide
EEFT
$3.19B
| $52K | ﹤0.01% |
600
+300
| +100% | +$28.8K |
|
6413
Fidus Investment
FDUS
$759M
| $52K | ﹤0.01% |
2,576
-13,882
| -84% | -$293K |
|
6414
PUT
Gladstone Investment Corp
GAIN
$642M
| $52K | ﹤0.01% |
3,800
-6,700
| -64% | -$94.4K |
|
|
GPMT
6415
CALL
Granite Point Mortgage Trust
GPMT
$63.7M
| $52K | ﹤0.01% |
17,500
+200
| +1% | +$552 |
|
6416
Disc Medicine
IRON
$2.81B
| $52K | ﹤0.01% |
800
+601
| +302% | +$35.8K |
|
6417
CALL
Krystal Biotech
KRYS
$10.7B
| $52K | ﹤0.01% |
300
-7,900
| -96% | -$1.18M |
|
|
KW
6418
PUT
DELISTED
Kennedy-Wilson Holdings
KW
| $52K | ﹤0.01% |
6,300
| – | – |
|
6419
CALL
Lineage Cell Therapeutics
LCTX
$264M
| $52K | ﹤0.01% |
31,000
-67,200
| -68% | -$79.5K |
|
6420
PUT
Lennox International
LII
$15B
| $52K | ﹤0.01% |
+100
| New | +$58.4K |
|
6421
El Pollo Loco
LOCO
$503M
| $52K | ﹤0.01% |
5,365
-5,646
| -51% | -$59.2K |
|
|
NOTE
6422
DELISTED
FiscalNote
NOTE
| $52K | ﹤0.01% |
11,257
+7,268
| +182% | +$47K |
|
6423
PUT
NET Power
NPWR
$120M
| $52K | ﹤0.01% |
17,300
-7,900
| -31% | -$21.1K |
|
6424
PUT
NerdWallet
NRDS
$632M
| $52K | ﹤0.01% |
4,900
-5,600
| -53% | -$59.7K |
|
6425
CALL
Oxford Industries
OXM
$581M
| $52K | ﹤0.01% |
1,300
+1,000
| +333% | +$43.3K |
|
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.