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 | |
|---|---|---|---|---|---|---|
2876
Huntsman Corp
HUN
$2.09B
| $776K | ﹤0.01% |
77,623
+24,684
| +47% | +$226K |
|
2877
PUT
Omnicom Group
OMC
$23.5B
| $775K | ﹤0.01% |
9,600
+5,000
| +109% | +$382K |
|
|
VTYX
2878
CALL
DELISTED
Ventyx Biosciences
VTYX
| $775K | ﹤0.01% |
85,800
+72,600
| +550% | +$543K |
|
2879
Cal-Maine
CALM
$4.18B
| $772K | ﹤0.01% |
+9,706
| New | +$852K |
|
|
HUMN
2880
Roundhill Humanoid Robotics ETF
HUMN
$78.8M
| $772K | ﹤0.01% |
25,840
+25,213
| +4,021% | +$743K |
|
2881
Cheesecake Factory
CAKE
$4.26B
| $770K | ﹤0.01% |
15,260
+12,240
| +405% | +$614K |
|
2882
PUT
KULR Technology Group
KULR
$119M
| $770K | ﹤0.01% |
260,200
-24,300
| -9% | -$89.2K |
|
2883
CALL
Rogers Communications
RCI
$17.7B
| $770K | ﹤0.01% |
20,400
+2,700
| +15% | +$101K |
|
2884
CALL
Turning Point Brands
TPB
$1.51B
| $770K | ﹤0.01% |
7,100
+2,500
| +54% | +$244K |
|
2885
PUT
Antero Midstream
AM
$10.6B
| $769K | ﹤0.01% |
43,200
+18,500
| +75% | +$333K |
|
2886
Revolution Medicines
RVMD
$40B
| $768K | ﹤0.01% |
+9,644
| New | +$632K |
|
2887
PUT
Moody's
MCO
$84.2B
| $766K | ﹤0.01% |
1,500
-3,900
| -72% | -$1.9M |
|
2888
Arch Capital
ACGL
$36.5B
| $766K | ﹤0.01% |
+7,988
| New | +$731K |
|
|
UNIT
2889
CALL
Uniti Group
UNIT
$2.58B
| $764K | ﹤0.01% |
109,000
+21,600
| +25% | +$137K |
|
2890
PUT
ADT
ADT
$5.26B
| $763K | ﹤0.01% |
94,600
+49,800
| +111% | +$414K |
|
2891
Burford Capital
BUR
$916M
| $763K | ﹤0.01% |
85,570
+4,825
| +6% | +$47.2K |
|
2892
Cadiz
CDZI
$249M
| $763K | ﹤0.01% |
135,949
-110,141
| -45% | -$591K |
|
2893
PUT
HubSpot
HUBS
$11.4B
| $762K | ﹤0.01% |
1,900
-12,600
| -87% | -$5.22M |
|
2894
YieldMax MSTR Option Income Strategy ETF
MSTY
$741M
| $762K | ﹤0.01% |
25,753
-10,963
| -30% | -$512K |
|
2895
PUT
Tyson Foods
TSN
$21.7B
| $762K | ﹤0.01% |
13,000
-47,000
| -78% | -$2.58M |
|
2896
Bath & Body Works
BBWI
$4.11B
| $760K | ﹤0.01% |
37,866
-125,843
| -77% | -$2.78M |
|
|
ARR
2897
CALL
Armour Residential REIT
ARR
$2.02B
| $759K | ﹤0.01% |
43,100
-38,000
| -47% | -$630K |
|
|
ARIS
2898
Aris Mining
ARIS
$3B
| $759K | ﹤0.01% |
46,747
+9,678
| +26% | +$119K |
|
2899
PUT
Lufax Holding
LU
$1.24B
| $757K | ﹤0.01% |
295,800
+189,500
| +178% | +$560K |
|
2900
PUT
argenx
ARGX
$56.2B
| $757K | ﹤0.01% |
900
-5,300
| -85% | -$4.54M |
|
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.