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 | |
|---|---|---|---|---|---|---|
1326
PUT
FuboTV Inc
FUBO
$245M
| $4.68M | ﹤0.01% |
154,808
+22,316
| +17% | +$891K |
|
|
QLTB
1327
PUT
DELISTED
ISHARES BAA BA RATED CORP BOND FUND
QLTB
| $4.67M | ﹤0.01% |
18,700
-10,100
| -35% | -$2.52M |
|
1328
PUT
B2Gold
BTG
$5.16B
| $4.67M | ﹤0.01% |
1,035,900
+349,400
| +51% | +$1.63M |
|
1329
CALL
Cummins
CMI
$91.7B
| $4.65M | ﹤0.01% |
9,100
+1,700
| +23% | +$795K |
|
1330
PUT
ProShares Ultra S&P500
SSO
$7.82B
| $4.62M | ﹤0.01% |
75,300
-21,700
| -22% | -$1.24M |
|
1331
Eldorado Gold
EGO
$8.31B
| $4.61M | ﹤0.01% |
128,456
+18,333
| +17% | +$549K |
|
1332
CALL
Factset
FDS
$9.05B
| $4.61M | ﹤0.01% |
15,900
-15,500
| -49% | -$4.35M |
|
1333
CALL
Enviri
NVRI
$621M
| $4.61M | ﹤0.01% |
257,400
+126,400
| +96% | +$1.88M |
|
1334
VanEck Junior Gold Miners ETF
GDXJ
$7.06B
| $4.61M | ﹤0.01% |
+40,492
| New | +$4.19M |
|
1335
Direxion Daily 20+ Year Treasury Bull 3X ETF
TMF
$2.22B
| $4.61M | ﹤0.01% |
123,450
-62,064
| -33% | -$2.51M |
|
1336
Axsome Therapeutics
AXSM
$12.4B
| $4.61M | ﹤0.01% |
25,222
+12,646
| +101% | +$1.77M |
|
1337
PUT
OppFi
OPFI
$770M
| $4.59M | ﹤0.01% |
439,000
+305,100
| +228% | +$3.09M |
|
1338
CALL
Bunge Global
BG
$23.6B
| $4.59M | ﹤0.01% |
51,500
-29,300
| -36% | -$2.7M |
|
|
KEEL
1339
PUT
Keel Infrastructure Corp
KEEL
$2.57B
| $4.59M | ﹤0.01% |
1,951,100
-985,500
| -34% | -$3.37M |
|
1340
Roundhill Generative AI & Technology ETF
CHAT
$1.8B
| $4.58M | ﹤0.01% |
77,702
-6,317
| -8% | -$392K |
|
1341
AES
AES
$10.6B
| $4.58M | ﹤0.01% |
319,055
-100,916
| -24% | -$1.42M |
|
1342
Verizon
VZ
$194B
| $4.57M | ﹤0.01% |
+112,170
| New | +$4.55M |
|
1343
PUT
Stanley Black & Decker
SWK
$14.2B
| $4.57M | ﹤0.01% |
61,500
-54,600
| -47% | -$3.84M |
|
1344
Ondas Inc
ONDS
$4.44B
| $4.56M | ﹤0.01% |
467,611
+291,174
| +165% | +$2.34M |
|
1345
Pan American Silver
PAAS
$18.6B
| $4.55M | ﹤0.01% |
87,892
-119,674
| -58% | -$5.01M |
|
1346
PUT
Fastenal
FAST
$54B
| $4.55M | ﹤0.01% |
113,300
+35,100
| +45% | +$1.48M |
|
1347
CALL
Monster Beverage
MNST
$91.4B
| $4.53M | ﹤0.01% |
59,100
+2,400
| +4% | +$172K |
|
1348
PUT
STMicroelectronics
STM
$46B
| $4.53M | ﹤0.01% |
174,500
+67,900
| +64% | +$1.74M |
|
1349
PUT
Golar LNG
GLNG
$4.95B
| $4.52M | ﹤0.01% |
121,600
-38,900
| -24% | -$1.49M |
|
1350
CALL
Doximity
DOCS
$3.67B
| $4.52M | ﹤0.01% |
102,100
-42,900
| -30% | -$2.41M |
|
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.