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 | |
|---|---|---|---|---|---|---|
|
PRMB
4126
CALL
Primo Brands
PRMB
$8.35B
| $222K | ﹤0.01% |
13,600
-29,100
| -68% | -$538K |
|
4127
Performance Food Group
PFGC
$18.3B
| $222K | ﹤0.01% |
2,472
-9,494
| -79% | -$917K |
|
|
MIAX
4128
PUT
Miami International Holdings
MIAX
$4.49B
| $222K | ﹤0.01% |
5,000
-31,500
| -86% | -$1.4M |
|
4129
PUT
CryoPort
CYRX
$753M
| $222K | ﹤0.01% |
23,100
-40,800
| -64% | -$385K |
|
4130
CALL
Extra Space Storage
EXR
$32.3B
| $221K | ﹤0.01% |
1,700
-3,100
| -65% | -$423K |
|
4131
EVgo
EVGO
$219M
| $221K | ﹤0.01% |
76,038
-61,019
| -45% | -$222K |
|
4132
CALL
Prosperity Bancshares
PB
$8.9B
| $221K | ﹤0.01% |
3,200
-200
| -6% | -$13.5K |
|
4133
CALL
Alliant Energy
LNT
$18.6B
| $221K | ﹤0.01% |
3,400
+900
| +36% | +$60.3K |
|
|
DVS
4134
PUT
DELISTED
Dolly Varden Silver Corp
DVS
| $221K | ﹤0.01% |
50,100
+49,400
| +7,057% | +$217K |
|
4135
Ero Copper
ERO
$2.64B
| $220K | ﹤0.01% |
7,792
-73,438
| -90% | -$1.71M |
|
4136
Utz Brands
UTZ
$1.24B
| $220K | ﹤0.01% |
21,208
+6,844
| +48% | +$73.8K |
|
4137
PUT
LegalZoom.com
LZ
$1.45B
| $219K | ﹤0.01% |
22,100
+19,900
| +905% | +$197K |
|
4138
CALL
Natural Resource Partners
NRP
$1.31B
| $219K | ﹤0.01% |
2,100
-6,000
| -74% | -$626K |
|
4139
CALL
Jack Henry & Associates
JKHY
$11.4B
| $219K | ﹤0.01% |
1,200
-2,700
| -69% | -$450K |
|
4140
iShares MSCI Chile ETF
ECH
$1,000M
| $219K | ﹤0.01% |
5,417
-10,677
| -66% | -$387K |
|
4141
PUT
Zedge
ZDGE
$38.3M
| $219K | ﹤0.01% |
66,700
+1,600
| +2% | +$4.63K |
|
4142
CALL
Rimini Street
RMNI
$457M
| $218K | ﹤0.01% |
56,300
+37,200
| +195% | +$154K |
|
4143
Stellus Capital Investment Corp
SCM
$205M
| $218K | ﹤0.01% |
17,222
+5,887
| +52% | +$72.2K |
|
4144
PUT
OGE Energy
OGE
$9.86B
| $218K | ﹤0.01% |
5,100
+1,300
| +34% | +$58K |
|
4145
CALL
Lear
LEA
$7.39B
| $218K | ﹤0.01% |
1,900
-1,100
| -37% | -$118K |
|
4146
PUT
Expro Ltd
XPRO
$1.66B
| $218K | ﹤0.01% |
16,300
-200
| -1% | -$2.7K |
|
4147
PUT
Morningstar
MORN
$7.55B
| $217K | ﹤0.01% |
1,000
+400
| +67% | +$86.6K |
|
|
NAKA
4148
PUT
Nakamoto Inc
NAKA
$74.5M
| $217K | ﹤0.01% |
15,470
-12,345
| -44% | -$323K |
|
|
PSIX
4149
Power Solutions International
PSIX
$586M
| $217K | ﹤0.01% |
3,802
-773
| -17% | -$55.2K |
|
4150
CALL
Peapack-Gladstone Financial
PGC
$815M
| $217K | ﹤0.01% |
7,800
+5,800
| +290% | +$158K |
|
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.