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 | |
|---|---|---|---|---|---|---|
951
CALL
S&P Global
SPGI
$124B
| $8.41M | ﹤0.01% |
16,100
+4,600
| +40% | +$2.28M |
|
952
PUT
Autodesk
ADSK
$43.3B
| $8.41M | ﹤0.01% |
28,400
-39,400
| -58% | -$11.9M |
|
953
CALL
IAMGOLD
IAG
$8.51B
| $8.39M | ﹤0.01% |
508,700
-22,000
| -4% | -$310K |
|
954
CALL
abrdn Physical Palladium Shares ETF
PALL
$609M
| $8.39M | ﹤0.01% |
288,500
+22,000
| +8% | +$593K |
|
955
PUT
Deckers Outdoor
DECK
$13.4B
| $8.37M | ﹤0.01% |
80,700
-32,000
| -28% | -$3M |
|
956
Home Depot
HD
$324B
| $8.37M | ﹤0.01% |
+24,312
| New | +$8.9M |
|
957
CALL
Plains All American Pipeline
PAA
$17.4B
| $8.36M | ﹤0.01% |
465,300
+128,600
| +38% | +$2.19M |
|
958
PUT
ProShares Ultra Bloomberg Natural Gas
BOIL
$423M
| $8.31M | ﹤0.01% |
146,000
-56,300
| -28% | -$3.44M |
|
959
PUT
Peabody Energy
BTU
$2.9B
| $8.31M | ﹤0.01% |
279,800
-202,500
| -42% | -$5.95M |
|
960
CALL
Sharplink Inc
SBET
$1.26B
| $8.31M | ﹤0.01% |
929,500
-625,300
| -40% | -$7.64M |
|
961
CALL
Direxion Daily MSCI Emerging Markets Bear 3X ETF
EDZ
$17.4M
| $8.31M | ﹤0.01% |
394,000
-302,200
| -43% | -$11.3M |
|
962
Vale
VALE
$63.1B
| $8.29M | ﹤0.01% |
+636,509
| New | +$7.73M |
|
963
CALL
Shift4
FOUR
$3.68B
| $8.28M | ﹤0.01% |
131,500
+14,300
| +12% | +$1.01M |
|
964
JD.com
JD
$40.6B
| $8.27M | ﹤0.01% |
288,008
-423,013
| -59% | -$13.2M |
|
965
PUT
Skyworks Solutions
SWKS
$9.1B
| $8.26M | ﹤0.01% |
130,300
-14,500
| -10% | -$1.01M |
|
966
CALL
Barclays
BCS
$93.3B
| $8.24M | ﹤0.01% |
323,900
-45,500
| -12% | -$1.01M |
|
967
Wayfair
W
$10.9B
| $8.23M | ﹤0.01% |
81,918
+31,890
| +64% | +$3.07M |
|
968
PUT
Cadence Design Systems
CDNS
$91.1B
| $8.22M | ﹤0.01% |
26,300
+4,100
| +18% | +$1.34M |
|
969
PUT
Under Armour Class C
UA
$2.81B
| $8.22M | ﹤0.01% |
1,656,600
+575,300
| +53% | +$2.56M |
|
970
PUT
Sarepta Therapeutics
SRPT
$1.68B
| $8.22M | ﹤0.01% |
381,800
-78,100
| -17% | -$1.65M |
|
971
CALL
Jabil
JBL
$33.7B
| $8.21M | ﹤0.01% |
36,000
-14,000
| -28% | -$2.99M |
|
972
PUT
Workday
WDAY
$31.6B
| $8.18M | ﹤0.01% |
38,100
-46,900
| -55% | -$10.7M |
|
973
PUT
Ralph Lauren
RL
$22.1B
| $8.17M | ﹤0.01% |
23,100
-700
| -3% | -$239K |
|
974
CALL
CME Group
CME
$91.9B
| $8.17M | ﹤0.01% |
29,900
-38,800
| -56% | -$10.5M |
|
975
PUT
PNC Financial Services
PNC
$99.5B
| $8.16M | ﹤0.01% |
39,100
-12,000
| -23% | -$2.32M |
|
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.