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 | |
|---|---|---|---|---|---|---|
|
GSRT
3951
DELISTED
GSR III Acquisition Corp
GSRT
| $454K | ﹤0.01% |
+43,913
| New | +$464K |
|
3952
PUT
Federal Agricultural Mortgage Class A
AGM.A
$1.62B
| $453K | ﹤0.01% |
2,700
+700
| +35% | +$94.8K |
|
3953
PUT
Celldex Therapeutics
CLDX
$2.79B
| $452K | ﹤0.01% |
17,500
-19,400
| -53% | -$450K |
|
3954
PUT
Onto Innovation
ONTO
$12B
| $452K | ﹤0.01% |
3,500
-1,900
| -35% | -$203K |
|
3955
PUT
Protagonist Therapeutics
PTGX
$8.8B
| $451K | ﹤0.01% |
6,800
-31,400
| -82% | -$1.78M |
|
|
ONIT
3956
PUT
Onity Group
ONIT
$341M
| $451K | ﹤0.01% |
11,300
-800
| -7% | -$32.1K |
|
3957
Bitwise Bitcoin ETF
BITB
$2.45B
| $450K | ﹤0.01% |
7,235
-33,765
| -82% | -$2.1M |
|
3958
CALL
Leslie's
LESL
$9.83M
| $450K | ﹤0.01% |
81,900
+81,650
| +32,660% | +$602K |
|
|
PSIX
3959
Power Solutions International
PSIX
$643M
| $449K | ﹤0.01% |
+4,575
| New | +$406K |
|
3960
Fortrea Holdings
FTRE
$1.96B
| $448K | ﹤0.01% |
53,297
+33,782
| +173% | +$259K |
|
3961
Quadratic Interest Rate Volatility and Inflation Hedge ETF
IVOL
$271M
| $448K | ﹤0.01% |
23,246
+22,996
| +9,198% | +$450K |
|
3962
PUT
Eastman Chemical
EMN
$7.79B
| $447K | ﹤0.01% |
7,100
+2,300
| +48% | +$161K |
|
3963
PUT
Revvity
RVTY
$12.4B
| $447K | ﹤0.01% |
5,100
+3,700
| +264% | +$336K |
|
3964
CALL
NOV
NOV
$7.11B
| $446K | ﹤0.01% |
33,700
-1,300
| -4% | -$16.8K |
|
3965
PUT
Stem
STEM
$47.7M
| $446K | ﹤0.01% |
25,500
-24,100
| -49% | -$341K |
|
3966
ProShares Ultra Semiconductors
USD
$2.35B
| $446K | ﹤0.01% |
9,022
-19,052
| -68% | -$824K |
|
|
TUYA
3967
Tuya Inc
TUYA
$1.02B
| $445K | ﹤0.01% |
180,391
+71,356
| +65% | +$179K |
|
3968
Lifestance Health
LFST
$4.29B
| $444K | ﹤0.01% |
+80,758
| New | +$396K |
|
3969
CALL
Lloyds Banking Group
LYG
$87.2B
| $444K | ﹤0.01% |
97,800
+84,700
| +647% | +$370K |
|
3970
CALL
Simply Good Foods
SMPL
$941M
| $444K | ﹤0.01% |
17,900
+17,600
| +5,867% | +$520K |
|
3971
Telesat
TSAT
$563M
| $444K | ﹤0.01% |
16,776
+6,919
| +70% | +$165K |
|
3972
Bruker
BRKR
$9.58B
| $443K | ﹤0.01% |
+13,647
| New | +$486K |
|
|
NA
3973
PUT
Nano Labs
NA
$40.9M
| $443K | ﹤0.01% |
82,100
+76,300
| +1,316% | +$454K |
|
|
VRNA
3974
CALL
DELISTED
Verona Pharma
VRNA
| $443K | ﹤0.01% |
25,000
-27,300
| -52% | -$2.85M |
|
3975
PUT
Public Service Enterprise Group
PEG
$39.3B
| $442K | ﹤0.01% |
5,300
-2,500
| -32% | -$210K |
|
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.