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 | |
|---|---|---|---|---|---|---|
601
PUT
Dow Inc
DOW
$21.3B
| $17.8M | 0.01% |
761,100
-288,900
| -28% | -$6.64M |
|
602
Nike
NKE
$57B
| $17.8M | 0.01% |
279,226
-257,066
| -48% | -$16.8M |
|
603
PUT
Expedia Group
EXPE
$35.8B
| $17.6M | 0.01% |
62,100
-3,000
| -5% | -$741K |
|
604
CALL
Wolfspeed
WOLF
$1.47B
| $17.5M | 0.01% |
1,007,500
-2,189,300
| -68% | -$50.2M |
|
|
EXE
605
CALL
Expand Energy Corp
EXE
$22.7B
| $17.5M | 0.01% |
329,200
+66,400
| +25% | +$7.36M |
|
606
PUT
Devon Energy
DVN
$52.9B
| $17.5M | 0.01% |
476,600
-136,500
| -22% | -$4.77M |
|
607
CALL
TJX Companies
TJX
$145B
| $17.3M | 0.01% |
112,800
-73,100
| -39% | -$10.8M |
|
608
PUT
Eaton
ETN
$160B
| $17.3M | 0.01% |
54,400
+5,400
| +11% | +$1.91M |
|
|
BULL
609
CALL
Webull Corp
BULL
$5.26B
| $17.3M | 0.01% |
2,229,200
+327,400
| +17% | +$3.29M |
|
|
CRWV
610
CoreWeave
CRWV
$49.3B
| $17.3M | 0.01% |
+241,594
| New | +$24.5M |
|
611
CALL
Okta
OKTA
$29.8B
| $17.3M | 0.01% |
199,800
-52,700
| -21% | -$4.6M |
|
612
AutoZone
AZO
$48.7B
| $17.3M | 0.01% |
5,092
+5,072
| +25,360% | +$19.2M |
|
613
PUT
UBS Group
UBS
$170B
| $17.2M | 0.01% |
372,000
+49,000
| +15% | +$1.98M |
|
614
PUT
Kraft Heinz
KHC
$29.5B
| $17.2M | 0.01% |
709,400
-39,700
| -5% | -$988K |
|
615
PUT
Cleveland-Cliffs
CLF
$7.13B
| $17M | 0.01% |
1,278,800
-187,100
| -13% | -$2.36M |
|
616
Dell
DELL
$339B
| $16.9M | 0.01% |
133,949
+118,653
| +776% | +$16.7M |
|
617
CALL
MGM Resorts International
MGM
$10.4B
| $16.8M | 0.01% |
460,500
+40,100
| +10% | +$1.36M |
|
618
Arm
ARM
$269B
| $16.8M | 0.01% |
153,416
+126,380
| +467% | +$18.4M |
|
619
PUT
Celsius Holdings
CELH
$7.76B
| $16.7M | 0.01% |
365,300
-162,000
| -31% | -$8.16M |
|
620
CALL
eBay
EBAY
$46B
| $16.7M | 0.01% |
191,500
-234,100
| -55% | -$20.3M |
|
621
PUT
Linde
LIN
$220B
| $16.7M | 0.01% |
39,100
+11,100
| +40% | +$4.75M |
|
622
Salesforce
CRM
$213B
| $16.6M | 0.01% |
62,567
-6,938
| -10% | -$1.72M |
|
|
IPFF
623
CALL
DELISTED
iShares International Preferred Stock ETF
IPFF
| $16.5M | 0.01% |
294,700
-49,700
| -14% | -$2.79M |
|
624
PUT
Zoom
ZM
$29.6B
| $16.5M | 0.01% |
191,400
-16,900
| -8% | -$1.42M |
|
625
CALL
D.R. Horton
DHI
$39.9B
| $16.5M | 0.01% |
114,300
-35,700
| -24% | -$5.44M |
|
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.