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 | Miscellaneous | 98.27% |
| 2 | Technology | 0.59% |
| 3 | Consumer Discretionary | 0.21% |
| 4 | Healthcare | 0.2% |
| 5 | Industrials | 0.18% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
301
PUT
AutoZone
AZO
$48.7B
| $48.2M | 0.03% |
14,200
-1,400
| -9% | -$5.29M |
|
302
PUT
Ford
F
$58.3B
| $47.7M | 0.03% |
3,636,500
+107,500
| +3% | +$1.39M |
|
303
CALL
MP Materials
MP
$9.71B
| $47.7M | 0.03% |
943,600
-322,800
| -25% | -$20.5M |
|
304
SoFi Technologies
SOFI
$23.5B
| $47.3M | 0.03% |
1,806,402
+198,421
| +12% | +$5.53M |
|
|
305
iShares Semiconductor ETF
SOXX
$42.8B
| $47M | 0.03% |
+156,093
| New | +$46M |
|
306
PUT
Celestica
CLS
$39.4B
| $46.8M | 0.03% |
158,200
-183,500
| -54% | -$55.3M |
|
307
CALL
ServiceNow
NOW
$146B
| $46.2M | 0.03% |
301,700
+33,700
| +13% | +$5.78M |
|
308
CALL
Apollo Global Management
APO
$78.9B
| $46M | 0.03% |
317,800
+102,900
| +48% | +$13.7M |
|
309
CALL
Riot Platforms
RIOT
$8.18B
| $45.8M | 0.03% |
3,617,600
-1,245,900
| -26% | -$21.3M |
|
310
CALL
SLB Ltd
SLB
$85.3B
| $45.7M | 0.03% |
1,189,900
+203,400
| +21% | +$7.37M |
|
|
311
PUT
Apollo Global Management
APO
$78.9B
| $45.6M | 0.03% |
315,300
+30,800
| +11% | +$4.09M |
|
|
OKLO
312
CALL
Oklo
OKLO
$7.68B
| $44.9M | 0.03% |
625,900
+22,000
| +4% | +$2.45M |
|
313
CALL
Roblox
RBLX
$30.9B
| $44.9M | 0.03% |
553,500
-131,300
| -19% | -$13.9M |
|
314
CALL
RTX Corp
RTX
$271B
| $44.7M | 0.03% |
243,900
-11,300
| -4% | -$1.96M |
|
315
PUT
Albemarle
ALB
$14.9B
| $44.6M | 0.03% |
315,500
-93,700
| -23% | -$10.6M |
|
316
PUT
Accenture
ACN
$114B
| $44.6M | 0.03% |
166,100
+11,200
| +7% | +$2.85M |
|
|
317
CALL
Western Digital
WDC
$169B
| $44.3M | 0.02% |
257,400
-430,400
| -63% | -$65.3M |
|
318
PUT
McDonald's
MCD
$181B
| $44.3M | 0.02% |
144,800
-107,200
| -43% | -$32.8M |
|
319
CALL
AbbVie
ABBV
$453B
| $44.1M | 0.02% |
193,200
+6,600
| +4% | +$1.5M |
|
320
CALL
GraniteShares Bloomberg Commodity Broad Strategy No K-1 ETF
COMB
$158M
| $43.8M | 0.02% |
674,900
-271,800
| -29% | -$6.11M |
|
321
CALL
Sea Limited
SE
$68.7B
| $43.7M | 0.02% |
342,400
-11,700
| -3% | -$1.73M |
|
322
CALL
Core Scientific
CORZ
$5.75B
| $43.5M | 0.02% |
2,988,300
-354,700
| -11% | -$6.18M |
|
323
PUT
Royal Caribbean
RCL
$70.9B
| $42.7M | 0.02% |
153,000
-21,500
| -12% | -$6.07M |
|
324
PUT
KKR & Co
KKR
$96.7B
| $42.6M | 0.02% |
334,500
-2,900
| -0.9% | -$361K |
|
|
SCIU
325
CALL
DELISTED
Global X Scientific Beta US ETF
SCIU
| $42.5M | 0.02% |
800,100
-218,400
| -21% | -$11.6M |
|
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's Q4 2025 filing shows 1,476 new, 2,599 increased, 4,088 reduced and 2,184 closed positions. Its largest new stake was Western Digital: 341,762 shares worth $58.9M. The largest sale was NVIDIA, an estimated $262M.
By sector, the portfolio is most concentrated in Miscellaneous at 98% of assets, up from 98% a quarter earlier, followed by Technology and Consumer Discretionary.
- 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.