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 | |
|---|---|---|---|---|---|---|
3276
PUT
JFrog
FROG
$9.84B
| $804K | ﹤0.01% |
17,000
+2,300
| +16% | +$104K |
|
3277
RB Global
RBA
$21.7B
| $800K | ﹤0.01% |
7,388
-13,247
| -64% | -$1.49M |
|
3278
U-Haul Holding Co
UHAL
$14.3B
| $800K | ﹤0.01% |
14,025
+13,943
| +17,004% | +$822K |
|
3279
PUT
Qiagen
QGEN
$8.47B
| $799K | ﹤0.01% |
17,900
+15,000
| +517% | +$718K |
|
|
GLDD
3280
CALL
DELISTED
Great Lakes Dredge & Dock
GLDD
| $798K | ﹤0.01% |
66,600
-9,900
| -13% | -$115K |
|
3281
Hannon Armstrong Sustainable Infrastructure Capital
HASI
$4.91B
| $797K | ﹤0.01% |
25,983
+3,481
| +15% | +$96K |
|
|
TWO
3282
Two Harbors Investment
TWO
$1.27B
| $797K | ﹤0.01% |
+80,825
| New | +$814K |
|
3283
Vista Energy
VIST
$7.42B
| $797K | ﹤0.01% |
+23,177
| New | +$959K |
|
|
IMSR
3284
Terrestrial Energy
IMSR
$541M
| $796K | ﹤0.01% |
+48,514
| New | +$577K |
|
3285
Corteva
CTVA
$58.6B
| $794K | ﹤0.01% |
11,751
+207
| +2% | +$15K |
|
3286
CALL
Rocket Pharmaceuticals
RCKT
$355M
| $794K | ﹤0.01% |
243,800
+99,800
| +69% | +$314K |
|
3287
CALL
Acuity Brands
AYI
$10.1B
| $792K | ﹤0.01% |
2,300
+1,200
| +109% | +$383K |
|
3288
CALL
Cedar Fair
FUN
$1.8B
| $792K | ﹤0.01% |
34,900
+16,100
| +86% | +$428K |
|
3289
PUT
MKS Inc
MKSI
$21.3B
| $792K | ﹤0.01% |
6,400
| – | – |
|
3290
Similarweb
SMWB
$598M
| $792K | ﹤0.01% |
85,222
+19,452
| +30% | +$174K |
|
3291
CALL
GFL Environmental
GFL
$14.1B
| $791K | ﹤0.01% |
16,700
+900
| +6% | +$43.6K |
|
3292
PUT
Recursion Pharmaceuticals
RXRX
$1.6B
| $790K | ﹤0.01% |
161,900
-241,700
| -60% | -$1.27M |
|
3293
PUT
Amprius Technologies
AMPX
$1.38B
| $789K | ﹤0.01% |
75,000
+39,600
| +112% | +$312K |
|
3294
PUT
Kura Oncology
KURA
$901M
| $789K | ﹤0.01% |
+89,200
| New | +$636K |
|
3295
abrdn Physical Gold Shares ETF
SGOL
$6.97B
| $789K | ﹤0.01% |
+21,435
| New | +$707K |
|
3296
CALL
Velocity Financial
VEL
$692M
| $789K | ﹤0.01% |
43,500
-12,900
| -23% | -$235K |
|
3297
PUT
Molson Coors Class B
TAP
$7.71B
| $787K | ﹤0.01% |
17,400
-126,500
| -88% | -$6.25M |
|
|
TGEN
3298
PUT
Tecogen Inc
TGEN
$99.9M
| $787K | ﹤0.01% |
+89,400
| New | +$717K |
|
3299
CALL
Dorian LPG
LPG
$1.88B
| $786K | ﹤0.01% |
26,400
+13,500
| +105% | +$405K |
|
3300
CALL
Offerpad Solutions
OPAD
$20.1M
| $786K | ﹤0.01% |
+18,870
| New | +$518K |
|
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.