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 | |
|---|---|---|---|---|---|---|
751
CALL
Viking Therapeutics
VKTX
$4.11B
| $15M | 0.01% |
572,100
+230,800
| +68% | +$6.89M |
|
752
CALL
HP
HPQ
$22.4B
| $14.9M | 0.01% |
548,600
-49,200
| -8% | -$1.31M |
|
753
CALL
Rubrik
RBRK
$14.9B
| $14.9M | 0.01% |
181,400
+123,400
| +213% | +$10.6M |
|
|
FIG
754
PUT
Figma
FIG
$10.6B
| $14.8M | 0.01% |
+286,100
| New | +$19.6M |
|
755
PUT
eBay
EBAY
$48.5B
| $14.8M | 0.01% |
162,300
-55,200
| -25% | -$4.88M |
|
756
CALL
Cenovus Energy
CVE
$55.4B
| $14.7M | 0.01% |
867,300
+26,100
| +3% | +$407K |
|
757
PUT
SiriusXM
SIRI
$10.1B
| $14.7M | 0.01% |
631,800
+317,400
| +101% | +$7.34M |
|
|
ETH
758
CALL
Grayscale Ethereum Staking Mini ETF Shares
ETH
$1.71B
| $14.7M | 0.01% |
375,300
+324,400
| +637% | +$12M |
|
759
PUT
KLA
KLAC
$286B
| $14.7M | 0.01% |
136,000
+41,000
| +43% | +$3.83M |
|
760
CALL
CoStar Group
CSGP
$11.1B
| $14.7M | 0.01% |
173,800
+27,900
| +19% | +$2.47M |
|
761
CALL
Nutanix
NTNX
$14.2B
| $14.6M | 0.01% |
196,800
-14,400
| -7% | -$1.06M |
|
762
CALL
MGM Resorts International
MGM
$11.5B
| $14.6M | 0.01% |
420,400
-104,900
| -20% | -$3.85M |
|
763
PUT
State Street SPDR Portfolio Europe ETF
SPEU
$707M
| $14.6M | 0.01% |
234,400
-341,500
| -59% | -$16.7M |
|
764
CALL
Blackrock
BLK
$161B
| $14.5M | 0.01% |
12,400
-5,400
| -30% | -$6.04M |
|
765
PUT
Rio Tinto
RIO
$149B
| $14.4M | 0.01% |
218,900
-195,000
| -47% | -$12.1M |
|
766
CALL
Pinterest
PINS
$12.3B
| $14.4M | 0.01% |
448,700
-376,900
| -46% | -$13.7M |
|
767
CALL
Peloton Interactive
PTON
$2.61B
| $14.4M | 0.01% |
1,601,700
-642,400
| -29% | -$4.78M |
|
768
PUT
QuantumScape Corp
QS
$3.15B
| $14.3M | 0.01% |
1,163,100
+419,500
| +56% | +$4.09M |
|
769
CALL
Zillow
Z
$6.77B
| $14.3M | 0.01% |
186,100
+53,800
| +41% | +$4.4M |
|
770
PUT
Take-Two Interactive
TTWO
$42.7B
| $14.3M | 0.01% |
55,400
-23,600
| -30% | -$5.59M |
|
771
CALL
Energy Fuels
UUUU
$3B
| $14.3M | 0.01% |
930,400
+422,700
| +83% | +$4.49M |
|
772
CALL
Nucor
NUE
$54.9B
| $14.3M | 0.01% |
105,300
-15,400
| -13% | -$2.18M |
|
773
CALL
Live Nation Entertainment
LYV
$41B
| $14.2M | 0.01% |
87,100
+9,300
| +12% | +$1.47M |
|
|
774
CALL
KLA
KLAC
$286B
| $14.1M | 0.01% |
131,000
-10,000
| -7% | -$933K |
|
775
Direxion Daily Financial Bull 3x ETF
FAS
$2.35B
| $14M | 0.01% |
78,784
-25,888
| -25% | -$4.44M |
|
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.