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 |
Netflix
NFLX
|
+$73.1M |
| 2 |
Western Digital
WDC
|
+$51.8M |
| 3 |
iShares Semiconductor ETF
SOXX
|
+$46M |
| 4 |
Meta Platforms (Facebook)
META
|
+$41.8M |
| 5 |
Alibaba
BABA
|
+$37.1M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
NVIDIA
NVDA
|
+$262M |
| 2 |
Microsoft
MSFT
|
+$194M |
| 3 |
iShares Russell 2000 ETF
IWM
|
+$149M |
| 4 |
Apple
AAPL
|
+$119M |
| 5 |
Amazon
AMZN
|
+$107M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 0.59% |
| 2 | Consumer Discretionary | 0.21% |
| 3 | Healthcare | 0.2% |
| 4 | Industrials | 0.18% |
| 5 | Communication Services | 0.16% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
676
CALL
Truist Financial
TFC
$63.2B
| $14.3M | 0.01% |
290,800
-4,500
| -2% | -$207K |
|
677
PUT
UiPath
PATH
$5.54B
| $14.3M | 0.01% |
872,300
+296,100
| +51% | +$4.61M |
|
678
CALL
Xtrackers MSCI Emerging Markets Hedged Equity ETF
DBEM
$108M
| $14.2M | 0.01% |
430,700
-1,909,300
| -82% | -$60.4M |
|
679
PUT
Energy Transfer Partners
ET
$70.1B
| $14.1M | 0.01% |
857,500
+173,000
| +25% | +$2.88M |
|
680
CALL
Lemonade
LMND
$4.87B
| $14.1M | 0.01% |
198,300
+11,600
| +6% | +$779K |
|
681
CALL
Kinross Gold
KGC
$28.9B
| $14.1M | 0.01% |
501,000
-350,400
| -41% | -$9.1M |
|
682
CALL
Carlyle Group
CG
$15.9B
| $14.1M | 0.01% |
237,700
+23,300
| +11% | +$1.32M |
|
683
CALL
HSBC
HSBC
$354B
| $14M | 0.01% |
182,400
+45,600
| +33% | +$3.26M |
|
|
TLN
684
CALL
Talen Energy Corp
TLN
$18B
| $14M | 0.01% |
37,400
-29,400
| -44% | -$11.4M |
|
685
CALL
Honeywell
HON
$73.8B
| $14M | 0.01% |
185,000
-66,881
| -27% | -$13.1M |
|
686
CALL
Atlassian
TEAM
$21.7B
| $13.9M | 0.01% |
85,900
+54,300
| +172% | +$8.52M |
|
687
CALL
ProShares Ultra S&P500
SSO
$8.02B
| $13.9M | 0.01% |
211,000
-15,600
| -7% | -$893K |
|
688
CALL
Zeta Global
ZETA
$5.03B
| $13.9M | 0.01% |
680,800
-95,200
| -12% | -$1.78M |
|
689
CALL
Fair Isaac
FICO
$28.3B
| $13.7M | 0.01% |
8,100
-8,900
| -52% | -$15.3M |
|
690
PUT
Toll Brothers
TOL
$13.9B
| $13.7M | 0.01% |
101,100
+31,000
| +44% | +$4.21M |
|
|
691
PUT
HSBC
HSBC
$354B
| $13.7M | 0.01% |
179,400
-58,500
| -25% | -$4.18M |
|
692
PUT
Blue Owl Capital
OWL
$6.19B
| $13.7M | 0.01% |
914,500
+412,000
| +82% | +$6.44M |
|
693
CALL
AstraZeneca
AZN
$263B
| $13.7M | 0.01% |
74,300
+28,100
| +61% | +$4.93M |
|
694
CALL
Opendoor
OPEN
$4.23B
| $13.6M | 0.01% |
5,913,400
-1,345,457
| -19% | -$9.64M |
|
695
Snowflake
SNOW
$92.8B
| $13.6M | 0.01% |
62,009
+41,711
| +205% | +$10.2M |
|
696
CALL
Marriott International
MAR
$97.5B
| $13.6M | 0.01% |
43,800
+14,500
| +49% | +$4.14M |
|
697
PUT
Quantum Computing Inc
QUBT
$1.78B
| $13.6M | 0.01% |
1,320,800
-790,100
| -37% | -$11.2M |
|
698
Boston Scientific
BSX
$63.9B
| $13.5M | 0.01% |
+141,877
| New | +$13.9M |
|
699
CALL
DexCom
DXCM
$27.6B
| $13.5M | 0.01% |
203,300
-20,800
| -9% | -$1.34M |
|
700
PUT
Constellation Brands
STZ
$22.6B
| $13.5M | 0.01% |
97,800
-45,200
| -32% | -$6.2M |
|
Similar funds
Simplex Trading's Q4 2025 Portfolio in Review
As of Q4 2025, Simplex Trading held 10,526 positions worth $177B, down 9% from $195B the previous quarter. Its ten largest holdings account for 49% of the portfolio.
Simplex Trading withdrew a net $23.2B in Q4 2025, closing 2,184 positions and reducing 4,088 holdings. Its most notable exit was iShares Russell 2000 ETF, an estimated $149M position sold in full.
By sector, the portfolio is most concentrated in Technology at 0.59% of assets, down from 0.79% a quarter earlier, followed by Consumer Discretionary and Healthcare.
Against the trend, Simplex Trading opened a new position in Western Digital worth $58.9M.
- Simplex Trading's largest Q4 2025 buy was Western Digital: 341,762 shares worth $58.9M.
- Simplex Trading added most to Netflix in Q4 2025, an estimated $73.1M increase.
- Simplex Trading's biggest Q4 2025 reduction was NVIDIA, cutting an estimated $262M.
- Simplex Trading fully exited iShares Russell 2000 ETF in Q4 2025, selling an estimated $149M.
- Simplex Trading's ten largest holdings make up 49% of its $177B portfolio in Q4 2025.
- Simplex Trading opened 1,476 new positions and closed 2,184 in Q4 2025.
- Simplex Trading's portfolio value fell 9% quarter-over-quarter to $177B.
Based on Simplex Trading's 13F filing for Q4 2025, filed 11 Feb 2026.