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 | |
|---|---|---|---|---|---|---|
1951
CALL
Capricor Therapeutics
CAPR
$1.14B
| $2.07M | ﹤0.01% |
71,700
-254,800
| -78% | -$3.33M |
|
1952
PUT
Century Aluminum
CENX
$4.57B
| $2.07M | ﹤0.01% |
52,800
+29,200
| +124% | +$912K |
|
1953
CALL
DaVita
DVA
$15.1B
| $2.07M | ﹤0.01% |
18,200
+2,700
| +17% | +$328K |
|
1954
CALL
Nutrien
NTR
$32.7B
| $2.07M | ﹤0.01% |
33,500
-136,700
| -80% | -$8.05M |
|
1955
Ciena
CIEN
$55.3B
| $2.07M | ﹤0.01% |
+8,836
| New | +$1.71M |
|
1956
CALL
RUM Group Inc
RUM
$1.57B
| $2.07M | ﹤0.01% |
326,800
-144,100
| -31% | -$988K |
|
1957
PUT
Tradeweb Markets
TW
$21.3B
| $2.06M | ﹤0.01% |
19,200
-22,700
| -54% | -$2.44M |
|
|
MDLN
1958
CALL
Medline Inc
MDLN
$32.8B
| $2.06M | ﹤0.01% |
+49,100
| New | +$2.07M |
|
1959
CALL
Saia
SAIA
$11.3B
| $2.06M | ﹤0.01% |
6,300
+3,800
| +152% | +$1.15M |
|
1960
PUT
Omeros
OMER
$709M
| $2.06M | ﹤0.01% |
119,700
+31,200
| +35% | +$269K |
|
|
CRON
1961
Cronos Group
CRON
$1.05B
| $2.06M | ﹤0.01% |
781,566
+426,214
| +120% | +$1.1M |
|
|
UNIT
1962
Uniti Group
UNIT
$2.63B
| $2.05M | ﹤0.01% |
292,751
+44,442
| +18% | +$282K |
|
1963
PUT
AptarGroup
ATR
$8.45B
| $2.05M | ﹤0.01% |
16,800
+6,300
| +60% | +$778K |
|
1964
CALL
Valvoline
VVV
$4.97B
| $2.05M | ﹤0.01% |
70,500
-26,300
| -27% | -$844K |
|
1965
Western Alliance Bancorporation
WAL
$9.07B
| $2.05M | ﹤0.01% |
24,365
+10,033
| +70% | +$815K |
|
1966
Capital One
COF
$124B
| $2.05M | ﹤0.01% |
+8,445
| New | +$1.88M |
|
1967
Compass
COMP
$8.27B
| $2.04M | ﹤0.01% |
+193,153
| New | +$1.76M |
|
1968
Eli Lilly
LLY
$1.07T
| $2.04M | ﹤0.01% |
1,899
-23,734
| -93% | -$22.7M |
|
|
CMA
1969
DELISTED
Comerica
CMA
| $2.04M | ﹤0.01% |
23,475
-6,005
| -20% | -$483K |
|
1970
CALL
W.R. Berkley
WRB
$28B
| $2.04M | ﹤0.01% |
29,100
+25,600
| +731% | +$1.89M |
|
1971
Enviri
NVRI
$621M
| $2.04M | ﹤0.01% |
113,638
+36,819
| +48% | +$549K |
|
1972
PUT
Altimmune
ALT
$539M
| $2.03M | ﹤0.01% |
562,600
+68,500
| +14% | +$299K |
|
1973
PUT
NexGen Energy
NXE
$6.05B
| $2.03M | ﹤0.01% |
220,300
+60,400
| +38% | +$533K |
|
|
BABO
1974
CALL
YieldMax BABA Option Income Strategy ETF
BABO
$13.7M
| $2.03M | ﹤0.01% |
127,000
-40,600
| -24% | -$617K |
|
1975
PUT
GDS Holdings
GDS
$6.34B
| $2.02M | ﹤0.01% |
58,000
-235,600
| -80% | -$8.15M |
|
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.