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 | |
|---|---|---|---|---|---|---|
876
PUT
Progressive
PGR
$120B
| $9.52M | 0.01% |
41,800
-3,900
| -9% | -$881K |
|
877
CALL
CRISPR Therapeutics
CRSP
$4.68B
| $9.5M | 0.01% |
181,200
-24,900
| -12% | -$1.49M |
|
878
CALL
Nutanix
NTNX
$14.2B
| $9.5M | 0.01% |
183,700
-13,100
| -7% | -$800K |
|
879
PUT
Align Technology
ALGN
$12B
| $9.49M | 0.01% |
60,800
+8,500
| +16% | +$1.22M |
|
880
PUT
Infosys
INFY
$43.2B
| $9.49M | 0.01% |
532,400
+414,100
| +350% | +$7.17M |
|
881
CALL
Amplify Online Retail ETF
IBUY
$106M
| $9.48M | 0.01% |
337,700
-844,100
| -71% | -$62.5M |
|
882
Kimberly-Clark
KMB
$35.6B
| $9.47M | 0.01% |
+93,843
| New | +$10.3M |
|
883
PUT
General Dynamics
GD
$103B
| $9.46M | 0.01% |
28,100
-7,700
| -22% | -$2.63M |
|
884
CALL
Stryker
SYK
$122B
| $9.45M | 0.01% |
26,900
+3,500
| +15% | +$1.28M |
|
|
SA
885
CALL
Seabridge Gold
SA
$2.8B
| $9.44M | 0.01% |
319,100
+82,100
| +35% | +$2.16M |
|
886
CALL
Compass
COMP
$8.05B
| $9.43M | 0.01% |
892,300
+407,100
| +84% | +$3.71M |
|
887
CALL
Emerson Electric
EMR
$81.2B
| $9.42M | 0.01% |
71,000
-6,900
| -9% | -$915K |
|
888
PUT
Invesco CurrencyShares Euro Currency Trust
FXE
$331M
| $9.41M | 0.01% |
86,800
+49,900
| +135% | +$5.36M |
|
889
CALL
Brinker International
EAT
$7.93B
| $9.4M | 0.01% |
65,500
-38,000
| -37% | -$4.98M |
|
890
PUT
First Majestic Silver
AG
$8.12B
| $9.38M | 0.01% |
563,300
-698,600
| -55% | -$9.71M |
|
891
CALL
Kohl's
KSS
$2.06B
| $9.38M | 0.01% |
459,600
-316,000
| -41% | -$5.92M |
|
892
CALL
Howmet Aerospace
HWM
$115B
| $9.37M | 0.01% |
45,700
-38,000
| -45% | -$7.56M |
|
893
PUT
ClearShares Piton Intermediate Fixed Income ETF
PIFI
$97.3M
| $9.34M | 0.01% |
322,900
+105,300
| +48% | +$10M |
|
894
PUT
Welltower
WELL
$174B
| $9.32M | 0.01% |
50,200
+17,200
| +52% | +$3.21M |
|
895
CALL
Amkor Technology
AMKR
$16.2B
| $9.31M | 0.01% |
235,900
+82,200
| +53% | +$2.93M |
|
896
PUT
United Rentals
URI
$71.4B
| $9.31M | 0.01% |
11,500
+600
| +6% | +$521K |
|
897
PUT
NuScale Power
SMR
$3.05B
| $9.28M | 0.01% |
654,800
-283,800
| -30% | -$8.12M |
|
898
CALL
Global Payments
GPN
$21.3B
| $9.27M | 0.01% |
119,800
-8,200
| -6% | -$660K |
|
899
PUT
Zillow
Z
$6.77B
| $9.27M | 0.01% |
135,900
-38,300
| -22% | -$2.77M |
|
900
PUT
VF Corp
VFC
$6.49B
| $9.24M | 0.01% |
510,800
-60,300
| -11% | -$977K |
|
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.