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 | |
|---|---|---|---|---|---|---|
1076
CALL
Uranium Energy
UEC
$4.86B
| $6.88M | ﹤0.01% |
589,400
-221,300
| -27% | -$2.9M |
|
1077
PUT
Nextpower Inc
NXT
$15.8B
| $6.87M | ﹤0.01% |
78,900
-108,500
| -58% | -$9.84M |
|
1078
Vistra
VST
$57B
| $6.87M | ﹤0.01% |
+42,592
| New | +$7.76M |
|
1079
General Motors
GM
$73B
| $6.82M | ﹤0.01% |
+83,865
| New | +$5.91M |
|
1080
CALL
PACCAR
PCAR
$68.8B
| $6.78M | ﹤0.01% |
61,900
+10,700
| +21% | +$1.1M |
|
1081
CALL
PACS Group
PACS
$7.09B
| $6.78M | ﹤0.01% |
176,500
+55,300
| +46% | +$1.21M |
|
1082
CALL
Realty Income
O
$60.4B
| $6.75M | ﹤0.01% |
119,700
-55,500
| -32% | -$3.21M |
|
1083
CALL
AngloGold Ashanti
AU
$39.7B
| $6.74M | ﹤0.01% |
79,000
-54,700
| -41% | -$4.27M |
|
1084
CALL
TripAdvisor
TRIP
$1.57B
| $6.74M | ﹤0.01% |
462,700
-99,500
| -18% | -$1.51M |
|
1085
Ross Stores
ROST
$74.5B
| $6.73M | ﹤0.01% |
37,382
+16,525
| +79% | +$2.76M |
|
1086
PUT
ProShares Ether Strategy ETF
EETH
$54.6M
| $6.73M | ﹤0.01% |
182,600
-419,000
| -70% | -$21M |
|
1087
PUT
Planet Fitness
PLNT
$4.29B
| $6.69M | ﹤0.01% |
61,700
+36,000
| +140% | +$3.71M |
|
1088
CALL
C.H. Robinson
CHRW
$24.2B
| $6.69M | ﹤0.01% |
41,600
-30,500
| -42% | -$4.51M |
|
1089
PUT
AeroVironment
AVAV
$8.03B
| $6.65M | ﹤0.01% |
27,500
-8,500
| -24% | -$2.67M |
|
1090
PUT
Peloton Interactive
PTON
$2.61B
| $6.64M | ﹤0.01% |
1,077,800
-698,600
| -39% | -$4.92M |
|
1091
CALL
Forward Air
FWRD
$490M
| $6.64M | ﹤0.01% |
265,500
+164,500
| +163% | +$3.7M |
|
1092
CALL
Edwards Lifesciences
EW
$48.3B
| $6.62M | ﹤0.01% |
77,700
-80,100
| -51% | -$6.57M |
|
1093
ServiceNow
NOW
$95.1B
| $6.61M | ﹤0.01% |
43,174
-8,326
| -16% | -$1.43M |
|
1094
Regeneron Pharmaceuticals
REGN
$68.3B
| $6.61M | ﹤0.01% |
8,559
+2,445
| +40% | +$1.66M |
|
1095
UiPath
PATH
$5.28B
| $6.61M | ﹤0.01% |
403,070
+121,669
| +43% | +$1.89M |
|
1096
PUT
NXP Semiconductors
NXPI
$70B
| $6.6M | ﹤0.01% |
30,400
+1,900
| +7% | +$407K |
|
1097
PUT
SoundHound AI
SOUN
$2.71B
| $6.59M | ﹤0.01% |
661,300
-27,400
| -4% | -$394K |
|
|
1098
PUT
Realty Income
O
$60.4B
| $6.58M | ﹤0.01% |
116,700
-50,700
| -30% | -$2.94M |
|
1099
CALL
O'Reilly Automotive
ORLY
$71.4B
| $6.58M | ﹤0.01% |
72,100
-2,300
| -3% | -$225K |
|
1100
CALL
Steel Dynamics
STLD
$34.7B
| $6.57M | ﹤0.01% |
38,800
-24,500
| -39% | -$3.89M |
|
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.