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 | |
|---|---|---|---|---|---|---|
251
PUT
Spotify
SPOT
$97.5B
| $57.7M | 0.03% |
99,400
-64,400
| -39% | -$40.3M |
|
252
PUT
AbbVie
ABBV
$448B
| $57.1M | 0.03% |
249,700
-58,100
| -19% | -$13.2M |
|
253
PUT
Texas Instruments
TXN
$268B
| $57M | 0.03% |
328,400
-111,500
| -25% | -$19.1M |
|
254
PUT
Baidu
BIDU
$36.6B
| $56.9M | 0.03% |
435,700
-270,300
| -38% | -$33.5M |
|
255
PUT
Intuitive Surgical
ISRG
$121B
| $56.8M | 0.03% |
100,300
+22,600
| +29% | +$12M |
|
256
CALL
DraftKings
DKNG
$11.3B
| $56.8M | 0.03% |
1,648,000
+157,700
| +11% | +$5.19M |
|
257
CALL
Coca-Cola
KO
$354B
| $56.7M | 0.03% |
811,300
-606,400
| -43% | -$42.3M |
|
258
CALL
Rocket Lab Corp
RKLB
$43.6B
| $56.5M | 0.03% |
810,600
-1,143,400
| -59% | -$65.5M |
|
|
259
CALL
Texas Instruments
TXN
$268B
| $56.5M | 0.03% |
325,700
+12,700
| +4% | +$2.17M |
|
260
PUT
GE Aerospace
GE
$354B
| $56.3M | 0.03% |
189,600
-40,800
| -18% | -$12.3M |
|
261
CALL
Tilray
TLRY
$514M
| $56.3M | 0.03% |
6,230,000
+5,828,260
| +1,451% | +$71.1M |
|
262
PUT
Starbucks
SBUX
$119B
| $55.9M | 0.03% |
663,500
-18,000
| -3% | -$1.52M |
|
|
B
263
PUT
Barrick Mining
B
$62.8B
| $55.6M | 0.03% |
1,277,800
-570,800
| -31% | -$21.4M |
|
264
PUT
Target
TGT
$62.6B
| $55.6M | 0.03% |
569,100
-478,600
| -46% | -$44.1M |
|
265
PUT
IonQ
IONQ
$12.9B
| $55.5M | 0.03% |
1,237,500
-862,600
| -41% | -$48.3M |
|
|
NBIS
266
PUT
Nebius Group N.V.
NBIS
$55.4B
| $55M | 0.03% |
657,100
-548,700
| -46% | -$56.9M |
|
|
SNDK
267
PUT
Sandisk
SNDK
$237B
| $55M | 0.03% |
231,700
+33,200
| +17% | +$6.65M |
|
268
PUT
Mastercard
MA
$470B
| $54.9M | 0.03% |
96,100
-6,700
| -7% | -$3.75M |
|
269
PUT
Occidental Petroleum
OXY
$57.2B
| $54.2M | 0.03% |
1,317,900
-139,400
| -10% | -$5.82M |
|
270
CALL
Hims & Hers Health
HIMS
$7.33B
| $54.2M | 0.03% |
1,668,800
+280,200
| +20% | +$12M |
|
271
CALL
Centene
CNC
$32.5B
| $54.1M | 0.03% |
1,315,200
-300,400
| -19% | -$11.2M |
|
272
PUT
Verizon
VZ
$185B
| $54M | 0.03% |
1,326,900
+496,000
| +60% | +$20.1M |
|
273
CALL
Pan American Silver
PAAS
$19.1B
| $54M | 0.03% |
1,042,900
+224,700
| +27% | +$9.41M |
|
274
Tesla
TSLA
$1.4T
| $54M | 0.03% |
120,091
-13,735
| -10% | -$6.09M |
|
275
PUT
Marathon Digital Holdings
MARA
$4.73B
| $53M | 0.03% |
5,896,900
-2,051,200
| -26% | -$30.3M |
|
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.