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 | |
|---|---|---|---|---|---|---|
6601
PUT
Hubbell
HUBB
$24.4B
| $43K | ﹤0.01% |
+100
| New | +$43K |
|
6602
LXP Industrial Trust
LXP
$3.52B
| $43K | ﹤0.01% |
+973
| New | +$41.8K |
|
6603
CALL
Methode Electronics
MEI
$458M
| $43K | ﹤0.01% |
5,700
-20,600
| -78% | -$153K |
|
6604
PUT
Middlesex Water
MSEX
$1.07B
| $43K | ﹤0.01% |
800
| – | – |
|
6605
PUT
Nkarta
NKTX
$152M
| $43K | ﹤0.01% |
20,800
+5,000
| +32% | +$10.3K |
|
|
NUVL
6606
PUT
DELISTED
Nuvalent
NUVL
| $43K | ﹤0.01% |
500
-1,000
| -67% | -$79.1K |
|
|
PNNT
6607
CALL
Pennant Park Investment Corp
PNNT
$220M
| $43K | ﹤0.01% |
6,500
-32,600
| -83% | -$232K |
|
6608
PUT
Q2 Holdings
QTWO
$3.78B
| $43K | ﹤0.01% |
600
-1,200
| -67% | -$98.6K |
|
6609
PUT
SK Telecom
SKM
$11.4B
| $43K | ﹤0.01% |
+2,000
| New | +$44.3K |
|
6610
CALL
Strategic Education
STRA
$1.98B
| $43K | ﹤0.01% |
500
+400
| +400% | +$32.2K |
|
|
TBI
6611
Trueblue
TBI
$227M
| $43K | ﹤0.01% |
7,023
+3,251
| +86% | +$20.6K |
|
6612
CALL
Telos
TLS
$331M
| $43K | ﹤0.01% |
6,300
-18,500
| -75% | -$88.4K |
|
6613
Motley Fool 100 Index ETF
TMFC
$1.99B
| $43K | ﹤0.01% |
+615
| New | +$41.3K |
|
6614
Tandem Diabetes Care
TNDM
$1.27B
| $43K | ﹤0.01% |
3,558
-6,876
| -66% | -$93.1K |
|
6615
PUT
Workiva
WK
$3.45B
| $43K | ﹤0.01% |
500
| – | – |
|
6616
W&T Offshore
WTI
$525M
| $43K | ﹤0.01% |
23,796
+5,159
| +28% | +$9.16K |
|
|
EMA
6617
CALL
Emera Inc
EMA
$16.5B
| $43K | ﹤0.01% |
+900
| New | +$42.1K |
|
|
SSK
6618
REX-Osprey SOL + Staking ETF
SSK
$68.7M
| $43K | ﹤0.01% |
+1,346
| New | +$40.8K |
|
6619
CALL
Codexis
CDXS
$158M
| $42K | ﹤0.01% |
17,400
+10,400
| +149% | +$28.4K |
|
6620
CMS Energy
CMS
$23.3B
| $42K | ﹤0.01% |
+585
| New | +$42K |
|
6621
PUT
Comtech Telecommunications
CMTL
$49.7M
| $42K | ﹤0.01% |
16,500
+13,100
| +385% | +$29.9K |
|
6622
CALL
DXC Technology
DXC
$1.91B
| $42K | ﹤0.01% |
3,100
-24,800
| -89% | -$352K |
|
6623
PUT
eGain
EGAN
$186M
| $42K | ﹤0.01% |
+4,900
| New | +$34K |
|
6624
PUT
Equity Lifestyle Properties
ELS
$13.1B
| $42K | ﹤0.01% |
700
+400
| +133% | +$24.3K |
|
|
EPIX
6625
CALL
DELISTED
ESSA Pharma
EPIX
| $42K | ﹤0.01% |
220,200
-16,500
| -7% | -$19.8K |
|
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.