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 | |
|---|---|---|---|---|---|---|
|
CMBT
1626
PUT
CMB.TECH NV
CMBT
$4.57B
| $3.12M | ﹤0.01% |
323,300
+149,700
| +86% | +$1.46M |
|
1627
PUT
Main Street Capital
MAIN
$4.97B
| $3.12M | ﹤0.01% |
51,600
-20,100
| -28% | -$1.19M |
|
|
GRAL
1628
PUT
GRAIL Inc
GRAL
$2.91B
| $3.12M | ﹤0.01% |
36,400
+25,300
| +228% | +$2.19M |
|
|
KLAR
1629
PUT
Klarna Group
KLAR
$6.56B
| $3.11M | ﹤0.01% |
107,600
+77,600
| +259% | +$2.66M |
|
1630
CALL
Southwest Airlines
LUV
$22.1B
| $3.11M | ﹤0.01% |
75,200
-287,800
| -79% | -$10.1M |
|
1631
PUT
Arbor Realty Trust
ABR
$960M
| $3.09M | ﹤0.01% |
398,100
-310,100
| -44% | -$3.04M |
|
1632
CALL
Ally Financial
ALLY
$13.1B
| $3.09M | ﹤0.01% |
68,200
-164,700
| -71% | -$6.79M |
|
1633
PUT
Clorox
CLX
$11.6B
| $3.09M | ﹤0.01% |
30,600
-29,000
| -49% | -$3.15M |
|
1634
CALL
Domino's
DPZ
$11B
| $3.08M | ﹤0.01% |
7,400
+3,400
| +85% | +$1.42M |
|
1635
PUT
Zoetis
ZTS
$31.6B
| $3.08M | ﹤0.01% |
24,500
-17,000
| -41% | -$2.22M |
|
1636
CALL
Innodata
INOD
$1.83B
| $3.08M | ﹤0.01% |
60,500
-10,000
| -14% | -$652K |
|
1637
CALL
Exelixis
EXEL
$13.9B
| $3.08M | ﹤0.01% |
70,200
-22,700
| -24% | -$939K |
|
1638
PUT
Comstock Resources
CRK
$3.97B
| $3.07M | ﹤0.01% |
132,600
+18,100
| +16% | +$399K |
|
|
VSXY
1639
CALL
Victoria's Secret
VSXY
$6.64B
| $3.07M | ﹤0.01% |
56,700
+6,000
| +12% | +$238K |
|
1640
PUT
Tractor Supply
TSCO
$16.3B
| $3.07M | ﹤0.01% |
61,400
-40,600
| -40% | -$2.19M |
|
1641
CALL
Amdocs
DOX
$5.53B
| $3.07M | ﹤0.01% |
38,100
+37,700
| +9,425% | +$3.03M |
|
1642
PUT
Qiagen
QGEN
$8.53B
| $3.07M | ﹤0.01% |
68,200
+50,300
| +281% | +$2.33M |
|
1643
CALL
Jefferies Financial Group
JEF
$12.9B
| $3.06M | ﹤0.01% |
49,400
+8,500
| +21% | +$487K |
|
1644
PUT
Entegris
ENTG
$19.7B
| $3.06M | ﹤0.01% |
36,300
+4,700
| +15% | +$408K |
|
|
KOCG
1645
CALL
DELISTED
FIS Knights of Columbus Global Belief ETF
KOCG
| $3.06M | ﹤0.01% |
58,600
-30,100
| -34% | -$1.57M |
|
1646
Direxion Daily Regional Banks Bull 3X ETF
DPST
$451M
| $3.06M | ﹤0.01% |
+30,248
| New | +$2.84M |
|
1647
Lemonade
LMND
$4.62B
| $3.05M | ﹤0.01% |
42,906
-5,849
| -12% | -$393K |
|
1648
Direxion Daily FTSE China Bull 3X ETF
YINN
$660M
| $3.05M | ﹤0.01% |
+71,661
| New | +$3.4M |
|
1649
CALL
Signet Jewelers
SIG
$3.55B
| $3.05M | ﹤0.01% |
36,800
-18,700
| -34% | -$1.78M |
|
1650
PUT
Tower Semiconductor
TSEM
$26.4B
| $3.04M | ﹤0.01% |
25,900
+12,900
| +99% | +$1.24M |
|
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.