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 | |
|---|---|---|---|---|---|---|
376
PUT
Applied Digital
APLD
$8.6B
| $33.8M | 0.02% |
1,379,200
-1,015,200
| -42% | -$29.2M |
|
377
CALL
Rigetti Computing
RGTI
$5.06B
| $33.6M | 0.02% |
1,517,600
+185,600
| +14% | +$6.05M |
|
378
CALL
Las Vegas Sands
LVS
$30B
| $33.6M | 0.02% |
515,600
+44,500
| +9% | +$2.73M |
|
379
CALL
Mastercard
MA
$470B
| $33.5M | 0.02% |
58,700
-44,600
| -43% | -$24.9M |
|
380
CALL
Cipher Digital
CIFR
$10B
| $33.4M | 0.02% |
2,266,200
-1,959,300
| -46% | -$34.6M |
|
381
CALL
Home Depot
HD
$330B
| $33.4M | 0.02% |
97,200
-75,900
| -44% | -$27.8M |
|
|
382
Alibaba
BABA
$279B
| $33.4M | 0.02% |
228,100
+227,757
| +66,401% | +$37.1M |
|
383
PUT
Riot Platforms
RIOT
$8.84B
| $33.3M | 0.02% |
2,631,700
-1,754,500
| -40% | -$30M |
|
|
XYZ
384
PUT
Block Inc
XYZ
$46.1B
| $33.2M | 0.02% |
510,800
-275,100
| -35% | -$19M |
|
385
PUT
Procter & Gamble
PG
$347B
| $33.2M | 0.02% |
231,700
-227,100
| -49% | -$33.5M |
|
386
CALL
Albemarle
ALB
$13.9B
| $32.9M | 0.02% |
232,900
+22,000
| +10% | +$2.5M |
|
387
CALL
Etsy
ETSY
$7.64B
| $32.9M | 0.02% |
592,900
-160,600
| -21% | -$9.8M |
|
388
PUT
KLA
KLAC
$280B
| $32.8M | 0.02% |
270,000
+134,000
| +99% | +$15.7M |
|
389
CALL
Regeneron Pharmaceuticals
REGN
$68.3B
| $32.6M | 0.02% |
42,200
+12,500
| +42% | +$8.49M |
|
390
PUT
Cigna
CI
$75.4B
| $32.4M | 0.02% |
117,800
-1,500
| -1% | -$421K |
|
391
CALL
ConocoPhillips
COP
$145B
| $32.4M | 0.02% |
346,300
-9,100
| -3% | -$823K |
|
|
ZVOL
392
CALL
Volatility Premium Plus ETF
ZVOL
$13.1M
| $32.4M | 0.02% |
1,232,200
+41,200
| +3% | +$461K |
|
393
CALL
Pinterest
PINS
$12.6B
| $32.3M | 0.02% |
1,249,000
+800,300
| +178% | +$23M |
|
394
CALL
Synopsys
SNPS
$72.3B
| $32.3M | 0.02% |
71,200
-89,100
| -56% | -$39.6M |
|
|
ECHO
395
PUT
EchoStar
ECHO
$26.7B
| $32.2M | 0.02% |
296,200
-617,700
| -68% | -$50.3M |
|
396
CALL
Dow Inc
DOW
$22.5B
| $31.9M | 0.02% |
1,363,200
+329,700
| +32% | +$7.58M |
|
|
FISV
397
CALL
Fiserv Inc
FISV
$26.8B
| $31.8M | 0.02% |
474,100
+246,800
| +109% | +$20.7M |
|
398
CALL
Boston Scientific
BSX
$63.9B
| $31.8M | 0.02% |
333,200
-134,900
| -29% | -$13.2M |
|
399
PUT
Eos Energy Enterprises
EOSE
$1.41B
| $31.7M | 0.02% |
2,767,800
+921,600
| +50% | +$13.2M |
|
400
PUT
State Street SPDR Portfolio Short Term Treasury ETF
SPTS
$6.06B
| $31.7M | 0.02% |
254,000
-144,800
| -36% | -$4.24M |
|
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.