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 | |
|---|---|---|---|---|---|---|
2776
Sportradar
SRAD
$4.34B
| $860K | ﹤0.01% |
+36,189
| New | +$870K |
|
2777
Axos Financial
AX
$5.45B
| $860K | ﹤0.01% |
9,980
+4,324
| +76% | +$356K |
|
2778
CALL
ImmunityBio
IBRX
$7.3B
| $859K | ﹤0.01% |
434,000
-186,300
| -30% | -$422K |
|
|
AMRZ
2779
Amrize Ltd
AMRZ
$27.6B
| $859K | ﹤0.01% |
15,876
+12,763
| +410% | +$651K |
|
2780
CALL
Solid Power
SLDP
$477M
| $857K | ﹤0.01% |
201,600
+93,400
| +86% | +$516K |
|
2781
PUT
PACS Group
PACS
$7.35B
| $856K | ﹤0.01% |
22,300
-22,400
| -50% | -$491K |
|
2782
CALL
TTM Technologies
TTMI
$12.6B
| $856K | ﹤0.01% |
12,400
-10,300
| -45% | -$672K |
|
2783
PUT
Brown-Forman Class B
BF.B
$12.3B
| $855K | ﹤0.01% |
32,800
-36,500
| -53% | -$1.03M |
|
2784
CALL
Eversource Energy
ES
$28.3B
| $855K | ﹤0.01% |
12,700
-6,300
| -33% | -$442K |
|
2785
CALL
Autoliv
ALV
$8.61B
| $855K | ﹤0.01% |
7,200
-11,600
| -62% | -$1.39M |
|
2786
Golar LNG
GLNG
$4.91B
| $854K | ﹤0.01% |
22,955
+20,022
| +683% | +$765K |
|
2787
CALL
Denali Therapeutics
DNLI
$3.76B
| $854K | ﹤0.01% |
51,700
+48,300
| +1,421% | +$815K |
|
2788
Crown Castle
CCI
$32.7B
| $853K | ﹤0.01% |
9,599
-1,757
| -15% | -$162K |
|
2789
CALL
Allegiant Air
ALGT
$2.65B
| $853K | ﹤0.01% |
10,000
-18,300
| -65% | -$1.31M |
|
2790
CALL
DTE Energy
DTE
$30.9B
| $851K | ﹤0.01% |
6,600
+3,800
| +136% | +$516K |
|
2791
PUT
TAL Education Group
TAL
$5.87B
| $851K | ﹤0.01% |
78,000
-4,700
| -6% | -$53.4K |
|
|
HITI
2792
PUT
High Tide
HITI
$189M
| $851K | ﹤0.01% |
321,100
+312,700
| +3,723% | +$928K |
|
2793
PUT
Dentsply Sirona
XRAY
$2.63B
| $849K | ﹤0.01% |
74,300
+9,100
| +14% | +$107K |
|
2794
CALL
Ralph Lauren
RL
$22.5B
| $849K | ﹤0.01% |
2,400
-4,200
| -64% | -$1.43M |
|
|
GAU
2795
Galiano Gold
GAU
$475M
| $845K | ﹤0.01% |
333,965
+320,070
| +2,303% | +$791K |
|
|
2796
TTM Technologies
TTMI
$12.6B
| $845K | ﹤0.01% |
12,244
-11,023
| -47% | -$719K |
|
2797
PUT
State Street SPDR S&P MIDCAP 400 ETF Trust
MDY
$26.7B
| $845K | ﹤0.01% |
1,400
-100
| -7% | -$59.8K |
|
2798
Ivanhoe Electric
IE
$1.45B
| $843K | ﹤0.01% |
52,761
+26,563
| +101% | +$380K |
|
2799
CALL
Equinix
EQIX
$104B
| $843K | ﹤0.01% |
1,100
-2,100
| -66% | -$1.65M |
|
2800
McCormick & Company Non-Voting
MKC
$13.7B
| $842K | ﹤0.01% |
12,366
-33,161
| -73% | -$2.2M |
|
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.