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 | |
|---|---|---|---|---|---|---|
151
PUT
Direxion Daily S&P Oil & Gas Exp. & Prod. Bull 2X ETF
GUSH
$247M
| $104M | 0.06% |
5,762,300
+2,204,400
| +62% | +$51.3M |
|
|
152
CALL
Direxion Daily S&P Oil & Gas Exp. & Prod. Bull 2X ETF
GUSH
$247M
| $103M | 0.06% |
6,122,200
+1,022,500
| +20% | +$23.8M |
|
153
PUT
Delta Air Lines
DAL
$55.7B
| $103M | 0.06% |
1,481,000
+235,400
| +19% | +$14.7M |
|
154
CALL
Occidental Petroleum
OXY
$56.2B
| $103M | 0.06% |
2,495,000
+280,900
| +13% | +$11.7M |
|
|
CRWV
155
PUT
CoreWeave
CRWV
$43.4B
| $102M | 0.06% |
1,429,800
-269,500
| -16% | -$27.3M |
|
156
CALL
Verizon
VZ
$183B
| $102M | 0.06% |
2,493,500
+1,015,900
| +69% | +$41.2M |
|
|
NVO
157
PUT
Novo Nordisk
NVO
$218B
| $100M | 0.06% |
1,968,800
+340,300
| +21% | +$17.4M |
|
158
CALL
Merck
MRK
$312B
| $99M | 0.06% |
940,400
+47,500
| +5% | +$4.46M |
|
159
CALL
Pfizer
PFE
$142B
| $97.5M | 0.06% |
3,916,800
-843,800
| -18% | -$21.3M |
|
160
CALL
Arista Networks
ANET
$220B
| $95.8M | 0.05% |
730,900
-255,600
| -26% | -$35.2M |
|
|
B
161
CALL
Barrick Mining
B
$60.9B
| $94.7M | 0.05% |
2,173,900
-165,000
| -7% | -$6.19M |
|
162
CALL
MongoDB
MDB
$24.7B
| $93.8M | 0.05% |
223,600
-41,600
| -16% | -$15.1M |
|
163
CALL
Warner Bros
WBD
$64.8B
| $93.2M | 0.05% |
3,234,000
-1,747,300
| -35% | -$40.8M |
|
164
CALL
Lam Research
LRCX
$403B
| $93.1M | 0.05% |
543,900
-110,400
| -17% | -$17.2M |
|
|
165
PUT
Pfizer
PFE
$142B
| $93M | 0.05% |
3,736,400
-245,100
| -6% | -$6.18M |
|
166
PUT
Bloom Energy
BE
$64.4B
| $92.8M | 0.05% |
1,067,500
-924,700
| -46% | -$97.2M |
|
167
CALL
Caterpillar
CAT
$410B
| $92.7M | 0.05% |
161,900
-17,100
| -10% | -$9.5M |
|
168
CALL
Baidu
BIDU
$36.8B
| $91.8M | 0.05% |
702,900
-542,000
| -44% | -$67.3M |
|
|
169
PUT
Caterpillar
CAT
$410B
| $91.4M | 0.05% |
159,500
+12,000
| +8% | +$6.67M |
|
170
PUT
Walt Disney
DIS
$167B
| $91.2M | 0.05% |
801,800
-186,800
| -19% | -$20.6M |
|
171
CALL
Vertiv
VRT
$117B
| $89.7M | 0.05% |
553,800
-114,400
| -17% | -$19.9M |
|
172
PUT
Vanguard S&P 500 ETF
VOO
$981B
| $88.9M | 0.05% |
182,500
-149,900
| -45% | -$93.2M |
|
|
NBIS
173
CALL
Nebius Group N.V.
NBIS
$55.1B
| $88.6M | 0.05% |
1,058,300
+68,900
| +7% | +$7.14M |
|
174
CALL
Freeport-McMoran
FCX
$89.9B
| $88M | 0.05% |
1,733,400
-1,292,300
| -43% | -$56M |
|
175
PUT
iShares MSCI Australia ETF
EWA
$1.34B
| $88M | 0.05% |
2,156,200
-758,100
| -26% | -$20.1M |
|
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.