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 | |
|---|---|---|---|---|---|---|
5726
PUT
Lear
LEA
$6.54B
| $45.8K | ﹤0.01% |
400
| – | – |
|
5727
PUT
Reynolds Consumer Products
REYN
$5.26B
| $45.8K | ﹤0.01% |
2,000
+100
| +5% | +$2.41K |
|
5728
BlackBerry
BB
$4.98B
| $45.7K | ﹤0.01% |
12,068
-170,843
| -93% | -$751K |
|
5729
OneSpan
OSPN
$574M
| $45.7K | ﹤0.01% |
+3,562
| New | +$48.3K |
|
5730
PUT
Hallador Energy
HNRG
$670M
| $45.7K | ﹤0.01% |
2,400
-66,000
| -96% | -$1.34M |
|
5731
Geron
GERN
$828M
| $45.7K | ﹤0.01% |
34,599
-29,003
| -46% | -$36.4K |
|
5732
CALL
Fabrinet
FN
$15.6B
| $45.5K | ﹤0.01% |
100
-4,900
| -98% | -$2.13M |
|
5733
PUT
Churchill Downs
CHDN
$5.88B
| $45.5K | ﹤0.01% |
400
-11,200
| -97% | -$1.16M |
|
5734
CALL
America Movil
AMX
$76.1B
| $45.5K | ﹤0.01% |
2,200
-200
| -8% | -$4.4K |
|
5735
CALL
CBIZ
CBZ
$2.99B
| $45.4K | ﹤0.01% |
900
| – | – |
|
5736
PUT
Tyler Technologies
TYL
$12.7B
| $45.4K | ﹤0.01% |
100
-200
| -67% | -$95.3K |
|
5737
CALL
KORU Medical Systems
KRMD
$189M
| $45.3K | ﹤0.01% |
7,800
+3,200
| +70% | +$15.3K |
|
5738
Cinemark Holdings
CNK
$4.24B
| $45.3K | ﹤0.01% |
1,948
-48,641
| -96% | -$1.28M |
|
5739
PUT
Woodside Energy
WDS
$44.6B
| $45.2K | ﹤0.01% |
2,900
-2,700
| -48% | -$42.9K |
|
|
RC
5740
Ready Capital
RC
$258M
| $45.2K | ﹤0.01% |
20,723
-6,063
| -23% | -$17K |
|
5741
Amplify Lithium & Battery Technology ETF
BATT
$115M
| $45.2K | ﹤0.01% |
3,273
+3,111
| +1,920% | +$42K |
|
5742
CALL
Neumora Therapeutics
NMRA
$298M
| $45.1K | ﹤0.01% |
25,200
-16,600
| -40% | -$36.3K |
|
5743
MillerKnoll
MLKN
$1.53B
| $45.1K | ﹤0.01% |
+2,466
| New | +$40.2K |
|
5744
CALL
TD Synnex
SNX
$20.4B
| $45.1K | ﹤0.01% |
300
-600
| -67% | -$92K |
|
5745
Amylyx Pharmaceuticals
AMLX
$2.26B
| $45K | ﹤0.01% |
+3,727
| New | +$50.6K |
|
5746
Bausch Health
BHC
$2.58B
| $45K | ﹤0.01% |
+6,478
| New | +$42.6K |
|
5747
First Trust Water ETF
FIW
$1.85B
| $44.9K | ﹤0.01% |
+413
| New | +$46.1K |
|
5748
PUT
RBC Bearings
RBC
$17.4B
| $44.8K | ﹤0.01% |
+100
| New | +$42.3K |
|
|
CRWL
5749
GraniteShares 2x Long CRWD Daily ETF
CRWL
$42.2M
| $44.8K | ﹤0.01% |
1,453
-4,580
| -76% | -$173K |
|
5750
Getty Images
GETY
$156M
| $44.7K | ﹤0.01% |
33,395
-37,022
| -53% | -$63.7K |
|
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.