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 | |
|---|---|---|---|---|---|---|
326
CALL
State Street SPDR S&P MIDCAP 400 ETF Trust
MDY
$27B
| $42.4M | 0.02% |
70,300
-33,200
| -32% | -$19.9M |
|
|
327
Meta Platforms (Facebook)
META
$1.59T
| $41.4M | 0.02% |
+62,668
| New | +$41.8M |
|
328
PUT
Trade Desk
TTD
$8.26B
| $41.2M | 0.02% |
1,084,500
-741,200
| -41% | -$32.9M |
|
329
PUT
Futu Holdings
FUTU
$14.9B
| $41.2M | 0.02% |
250,700
-106,400
| -30% | -$18.3M |
|
330
CALL
General Motors
GM
$74.1B
| $41.1M | 0.02% |
505,600
-447,700
| -47% | -$31.6M |
|
331
PUT
iShares Gold Trust
IAU
$64.2B
| $40.8M | 0.02% |
502,900
-75,400
| -13% | -$5.9M |
|
332
CALL
Vistra
VST
$56.2B
| $40.8M | 0.02% |
252,800
-137,500
| -35% | -$25M |
|
333
PUT
Avis
CAR
$5.81B
| $40.5M | 0.02% |
316,000
+36,900
| +13% | +$5.15M |
|
334
PUT
RTX Corp
RTX
$262B
| $40.3M | 0.02% |
219,900
+33,700
| +18% | +$5.85M |
|
335
Intel
INTC
$516B
| $39.9M | 0.02% |
1,082,246
-1,747,358
| -62% | -$66M |
|
336
PUT
Unity
U
$12.8B
| $39.9M | 0.02% |
903,700
-232,900
| -20% | -$9.49M |
|
337
PUT
Moderna
MRNA
$23B
| $39.8M | 0.02% |
1,348,500
-304,600
| -18% | -$8.28M |
|
338
CALL
XPeng
XPEV
$12.3B
| $39.7M | 0.02% |
1,958,900
+721,700
| +58% | +$15.7M |
|
339
PUT
Airbnb
ABNB
$83.1B
| $39.6M | 0.02% |
291,900
-139,800
| -32% | -$17.4M |
|
340
PUT
Roku
ROKU
$21.2B
| $39.3M | 0.02% |
362,700
-83,700
| -19% | -$8.49M |
|
341
PUT
AT&T
T
$160B
| $39.3M | 0.02% |
1,583,600
-142,900
| -8% | -$3.62M |
|
|
TEM
342
CALL
Tempus AI
TEM
$8.43B
| $39.2M | 0.02% |
663,500
-122,300
| -16% | -$9.57M |
|
343
PUT
YieldMax TSLA Option Income Strategy ETF
TSLY
$730M
| $38.9M | 0.02% |
+1,081,500
| New | +$43.7M |
|
344
Cigna
CI
$75.4B
| $38.5M | 0.02% |
140,025
+6,797
| +5% | +$1.91M |
|
345
CALL
Shell
SHEL
$243B
| $38.5M | 0.02% |
523,700
-147,300
| -22% | -$10.9M |
|
346
CALL
Amgen
AMGN
$198B
| $38.4M | 0.02% |
117,200
+13,100
| +13% | +$4.16M |
|
347
PUT
Philip Morris
PM
$303B
| $38.3M | 0.02% |
238,900
-96,700
| -29% | -$15M |
|
348
PUT
Blackstone
BX
$150B
| $38M | 0.02% |
246,800
-74,300
| -23% | -$11.3M |
|
349
CALL
T-Mobile US
TMUS
$207B
| $37.9M | 0.02% |
186,600
+61,500
| +49% | +$13M |
|
350
Pfizer
PFE
$141B
| $37.1M | 0.02% |
1,491,037
+194,547
| +15% | +$4.91M |
|
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.