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 | |
|---|---|---|---|---|---|---|
2426
Yext
YEXT
$501M
| $1.23M | ﹤0.01% |
152,479
+136,538
| +857% | +$1.15M |
|
|
LENZ
2427
CALL
LENZ Therapeutics
LENZ
$172M
| $1.23M | ﹤0.01% |
76,800
+74,400
| +3,100% | +$2.17M |
|
2428
Nasdaq
NDAQ
$51.5B
| $1.23M | ﹤0.01% |
12,647
-9,394
| -43% | -$845K |
|
2429
Paychex
PAYX
$40.4B
| $1.23M | ﹤0.01% |
+10,935
| New | +$1.28M |
|
2430
CALL
Ovintiv
OVV
$17.5B
| $1.23M | ﹤0.01% |
31,300
-75,000
| -71% | -$2.91M |
|
2431
TG Therapeutics
TGTX
$8.58B
| $1.22M | ﹤0.01% |
41,042
+24,508
| +148% | +$800K |
|
2432
PUT
Star Bulk Carriers
SBLK
$3.14B
| $1.22M | ﹤0.01% |
63,600
+9,000
| +16% | +$168K |
|
2433
CALL
Cabaletta Bio
CABA
$439M
| $1.22M | ﹤0.01% |
557,300
-136,400
| -20% | -$338K |
|
2434
PUT
Howard Hughes
HHH
$3.93B
| $1.22M | ﹤0.01% |
15,300
+10,900
| +248% | +$903K |
|
2435
Franco-Nevada
FNV
$41.4B
| $1.22M | ﹤0.01% |
+5,886
| New | +$1.19M |
|
2436
CALL
FIGS
FIGS
$1.59B
| $1.22M | ﹤0.01% |
107,300
-45,700
| -30% | -$428K |
|
2437
Vanguard Real Estate ETF
VNQ
$39.9B
| $1.22M | ﹤0.01% |
13,744
-40,742
| -75% | -$3.66M |
|
|
P
2438
Everpure Inc
P
$24.8B
| $1.22M | ﹤0.01% |
+18,146
| New | +$1.52M |
|
2439
CALL
nCino
NCNO
$1.81B
| $1.22M | ﹤0.01% |
47,400
+25,700
| +118% | +$653K |
|
|
NVMI
2440
CALL
Nova
NVMI
$13.9B
| $1.22M | ﹤0.01% |
3,700
-7,700
| -68% | -$2.48M |
|
2441
PUT
MarketAxess Holdings
MKTX
$4.15B
| $1.21M | ﹤0.01% |
6,700
+2,400
| +56% | +$410K |
|
2442
CALL
Vital Farms
VITL
$558M
| $1.21M | ﹤0.01% |
38,000
-5,300
| -12% | -$187K |
|
2443
CALL
Immunome
IMNM
$2.52B
| $1.21M | ﹤0.01% |
56,500
+11,100
| +24% | +$195K |
|
2444
PUT
IDEAYA Biosciences
IDYA
$3.41B
| $1.21M | ﹤0.01% |
35,100
+32,400
| +1,200% | +$1.03M |
|
2445
Flex
FLEX
$43.4B
| $1.21M | ﹤0.01% |
20,054
-7,055
| -26% | -$436K |
|
2446
PUT
Sundial Growers
SNDL
$325M
| $1.21M | ﹤0.01% |
727,400
+128,400
| +21% | +$258K |
|
2447
CALL
Global X MSCI Norway ETF
NORW
$86.5M
| $1.21M | ﹤0.01% |
24,700
+14,500
| +142% | +$426K |
|
2448
YieldMax Ultra Option Income Strategy ETF
ULTY
$800M
| $1.21M | ﹤0.01% |
32,294
+5,571
| +21% | +$251K |
|
2449
Qiagen
QGEN
$8.53B
| $1.2M | ﹤0.01% |
26,774
+17,356
| +184% | +$803K |
|
2450
CALL
NGL Energy Partners
NGL
$1.94B
| $1.2M | ﹤0.01% |
120,400
-800
| -0.7% | -$6.71K |
|
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.