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 | Miscellaneous | 98.27% |
| 2 | Technology | 0.59% |
| 3 | Consumer Discretionary | 0.21% |
| 4 | Healthcare | 0.2% |
| 5 | Industrials | 0.18% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
776
CALL
StoneCo
STNE
$2.33B
| $11.4M | 0.01% |
767,800
-252,000
| -25% | -$4.21M |
|
|
BNY
777
CALL
Bank of New York Mellon
BNY
$112B
| $11.3M | 0.01% |
97,700
-16,200
| -14% | -$1.79M |
|
|
QXO
778
CALL
QXO Inc
QXO
$13.9B
| $11.3M | 0.01% |
587,000
+116,800
| +25% | +$2.24M |
|
779
PUT
Tapestry
TPR
$24.4B
| $11.3M | 0.01% |
88,500
+8,300
| +10% | +$949K |
|
780
CALL
MetLife
MET
$62B
| $11.2M | 0.01% |
142,000
-2,100
| -1% | -$166K |
|
781
CALL
YieldMax TSLA Option Income Strategy ETF
TSLY
$663M
| $11.2M | 0.01% |
+338,500
| New | +$13.7M |
|
|
B
782
Barrick Mining
B
$73.7B
| $11.2M | 0.01% |
+256,167
| New | +$9.61M |
|
783
CALL
Dominion Energy
D
$57.9B
| $11.2M | 0.01% |
190,400
-67,100
| -26% | -$4.04M |
|
784
Southwest Airlines
LUV
$19.4B
| $11.1M | 0.01% |
+268,783
| New | +$9.39M |
|
785
CALL
EOG Resources
EOG
$76.2B
| $11.1M | 0.01% |
105,700
-17,600
| -14% | -$1.89M |
|
786
PUT
Enphase Energy
ENPH
$4.81B
| $11.1M | 0.01% |
346,200
+16,500
| +5% | +$534K |
|
787
CALL
Sable Offshore Corp
SOC
$909M
| $11.1M | 0.01% |
1,226,300
+115,700
| +10% | +$1.09M |
|
|
P
788
CALL
Everpure Inc
P
$33.1B
| $11.1M | 0.01% |
165,000
-132,900
| -45% | -$11.1M |
|
789
CALL
UBS Group
UBS
$170B
| $11.1M | 0.01% |
238,700
+20,000
| +9% | +$808K |
|
790
CALL
C3.ai
AI
$1.67B
| $11M | 0.01% |
818,200
-349,800
| -30% | -$5.58M |
|
791
CALL
Johnson Controls International
JCI
$87.8B
| $11M | 0.01% |
92,100
-166,000
| -64% | -$19.1M |
|
|
FISV
792
PUT
Fiserv Inc
FISV
$28.2B
| $11M | 0.01% |
164,000
-16,300
| -9% | -$1.36M |
|
793
PUT
General Mills
GIS
$20.5B
| $11M | 0.01% |
236,700
-141,400
| -37% | -$6.72M |
|
|
EH
794
CALL
EHang Holdings
EH
$356M
| $11M | 0.01% |
831,900
+320,400
| +63% | +$5.06M |
|
795
PUT
Upstart Holdings
UPST
$2.73B
| $10.9M | 0.01% |
249,400
-302,300
| -55% | -$13.9M |
|
796
CALL
Samsara
IOT
$23.4B
| $10.9M | 0.01% |
306,900
-113,700
| -27% | -$4.4M |
|
797
CALL
RH
RH
$2.8B
| $10.9M | 0.01% |
60,700
-3,200
| -5% | -$547K |
|
798
PUT
Mondelez International
MDLZ
$78.2B
| $10.9M | 0.01% |
201,600
+90,300
| +81% | +$5.2M |
|
|
CFLT
799
DELISTED
Confluent
CFLT
| $10.8M | 0.01% |
+358,415
| New | +$8.8M |
|
800
CALL
Lennar Class A
LEN
$20.1B
| $10.8M | 0.01% |
155,500
-152,400
| -49% | -$18.4M |
|
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's Q4 2025 filing shows 1,476 new, 2,599 increased, 4,088 reduced and 2,184 closed positions. Its largest new stake was Western Digital: 341,762 shares worth $58.9M. The largest sale was NVIDIA, an estimated $262M.
By sector, the portfolio is most concentrated in Miscellaneous at 98% of assets, up from 98% a quarter earlier, followed by Technology and Consumer Discretionary.
- 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.