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 | |
|---|---|---|---|---|---|---|
|
XXI
2701
PUT
Twenty One Capital Inc
XXI
$1.57B
| $927K | ﹤0.01% |
+105,800
| New | +$1.1M |
|
|
SEZL
2702
CALL
Sezzle
SEZL
$5.17B
| $927K | ﹤0.01% |
14,600
-1,300
| -8% | -$88.6K |
|
2703
PUT
Ouster
OUST
$2.29B
| $926K | ﹤0.01% |
42,800
-97,400
| -69% | -$2.57M |
|
2704
LPL Financial
LPLA
$26.3B
| $926K | ﹤0.01% |
2,592
+2,542
| +5,084% | +$899K |
|
2705
CALL
Ternium
TX
$9.29B
| $924K | ﹤0.01% |
24,200
+12,500
| +107% | +$459K |
|
2706
CALL
Iovance Biotherapeutics
IOVA
$2.23B
| $923K | ﹤0.01% |
338,000
+12,700
| +4% | +$29.4K |
|
|
HTGCR
2707
PUT
DELISTED
HERCULES TECHNOLOGY GROWTH CAP INC TRANS RGTS TO PUR COM STK
HTGCR
| $922K | ﹤0.01% |
49,000
+16,300
| +50% | +$307K |
|
2708
CALL
Portillo's
PTLO
$315M
| $920K | ﹤0.01% |
202,700
+106,700
| +111% | +$557K |
|
2709
PUT
Kornit Digital
KRNT
$706M
| $919K | ﹤0.01% |
63,900
+63,600
| +21,200% | +$871K |
|
2710
CALL
Ivanhoe Electric
IE
$1.43B
| $919K | ﹤0.01% |
57,500
-163,500
| -74% | -$2.34M |
|
2711
CALL
Coca-Cola Femsa
KOF
$21.6B
| $919K | ﹤0.01% |
9,700
+7,500
| +341% | +$662K |
|
|
XXI
2712
CALL
Twenty One Capital Inc
XXI
$1.57B
| $917K | ﹤0.01% |
+104,700
| New | +$1.09M |
|
2713
PUT
Range Resources
RRC
$9.11B
| $917K | ﹤0.01% |
26,000
-68,400
| -72% | -$2.55M |
|
2714
ArriVent BioPharma
AVBP
$1.48B
| $917K | ﹤0.01% |
45,558
+38,104
| +511% | +$793K |
|
2715
PUT
Kura Oncology
KURA
$922M
| $914K | ﹤0.01% |
88,000
-1,200
| -1% | -$12.6K |
|
2716
PUT
Fox Class B
FOX
$20.7B
| $914K | ﹤0.01% |
12,600
+700
| +6% | +$40.9K |
|
|
AMRZ
2717
CALL
Amrize Ltd
AMRZ
$27.3B
| $914K | ﹤0.01% |
16,900
-800
| -5% | -$40.8K |
|
2718
Labcorp
LH
$24.3B
| $914K | ﹤0.01% |
3,642
+714
| +24% | +$190K |
|
2719
iShares China Large-Cap ETF
FXI
$4.31B
| $909K | ﹤0.01% |
+23,742
| New | +$942K |
|
2720
CALL
Modine Manufacturing
MOD
$12.8B
| $908K | ﹤0.01% |
6,800
-3,600
| -35% | -$536K |
|
|
FRMM
2721
PUT
Forum Markets
FRMM
$75.7M
| $907K | ﹤0.01% |
185,200
+181,620
| +5,073% | +$2.56M |
|
2722
PUT
Sysco
SYY
$39.7B
| $906K | ﹤0.01% |
12,300
-7,200
| -37% | -$548K |
|
2723
Funko
FNKO
$323M
| $906K | ﹤0.01% |
266,363
-23,507
| -8% | -$73.9K |
|
2724
PUT
Stoke Therapeutics
STOK
$1.82B
| $905K | ﹤0.01% |
28,500
+25,300
| +791% | +$761K |
|
2725
CALL
Burford Capital
BUR
$907M
| $904K | ﹤0.01% |
101,400
-65,800
| -39% | -$644K |
|
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.