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 | |
|---|---|---|---|---|---|---|
5801
SmartRent
SMRT
$195M
| $42.9K | ﹤0.01% |
21,226
-4,486
| -17% | -$7.35K |
|
5802
PUT
Spero Therapeutics
SPRO
$67.7M
| $42.9K | ﹤0.01% |
18,400
-9,700
| -35% | -$22.5K |
|
|
ETU
5803
T-Rex 2X Long Ether Daily Target ETF
ETU
$10.8M
| $42.8K | ﹤0.01% |
2,968
-158
| -5% | -$3.54K |
|
|
ZEUS
5804
PUT
DELISTED
Olympic Steel
ZEUS
| $42.8K | ﹤0.01% |
1,000
+800
| +400% | +$28.5K |
|
5805
iShares MSCI Global Gold Miners ETF
RING
$2.27B
| $42.8K | ﹤0.01% |
581
+252
| +77% | +$17K |
|
5806
CALL
Aviat Networks
AVNW
$265M
| $42.8K | ﹤0.01% |
2,000
-1,500
| -43% | -$33.5K |
|
|
ABX
5807
CALL
Abacus Global Management
ABX
$989M
| $42.8K | ﹤0.01% |
5,000
-5,800
| -54% | -$38.2K |
|
5808
Clean Harbors
CLH
$16.5B
| $42.7K | ﹤0.01% |
182
+3
| +2% | +$685 |
|
|
ATXS
5809
DELISTED
Astria Therapeutics
ATXS
| $42.6K | ﹤0.01% |
3,257
+1,040
| +47% | +$12.4K |
|
|
QTOP
5810
iShares Nasdaq Top 30 Stocks ETF
QTOP
$281M
| $42.6K | ﹤0.01% |
1,334
-2,630
| -66% | -$83.8K |
|
|
TSYY
5811
GraniteShares YieldBOOST TSLA ETF
TSYY
$63.2M
| $42.6K | ﹤0.01% |
+960
| New | +$52.9K |
|
|
PPIH
5812
CALL
Perma-Pipe International
PPIH
$196M
| $42.5K | ﹤0.01% |
1,400
-4,600
| -77% | -$126K |
|
5813
Stratasys
SSYS
$679M
| $42.5K | ﹤0.01% |
+4,895
| New | +$48.5K |
|
5814
PUT
Deluxe
DLX
$1.18B
| $42.4K | ﹤0.01% |
1,900
+800
| +73% | +$16.1K |
|
|
CTO
5815
PUT
CTO Realty Growth
CTO
$824M
| $42.3K | ﹤0.01% |
2,300
-600
| -21% | -$10.3K |
|
|
ORGN
5816
CALL
DELISTED
Origin Materials
ORGN
| $42.3K | ﹤0.01% |
6,667
-903
| -12% | -$13.2K |
|
5817
CALL
AlTi Global
ALTI
$399M
| $42.2K | ﹤0.01% |
+9,100
| New | +$37.6K |
|
5818
PUT
Universal Corp
UVV
$1.31B
| $42.2K | ﹤0.01% |
800
-1,400
| -64% | -$74.4K |
|
5819
PUT
Simply Good Foods
SMPL
$901M
| $42.2K | ﹤0.01% |
2,100
-300
| -13% | -$6.24K |
|
5820
InfraCap MLP ETF
AMZA
$470M
| $42.1K | ﹤0.01% |
+1,066
| New | +$42.1K |
|
|
LTM
5821
LATAM Airlines Group S.A.
LTM
$15.1B
| $42.1K | ﹤0.01% |
+779
| New | +$36.9K |
|
5822
CALL
PSQ Holdings
PSQH
$13.9M
| $42K | ﹤0.01% |
2,720
+740
| +37% | +$18.3K |
|
5823
PUT
Porch Group
PRCH
$1.64B
| $42K | ﹤0.01% |
4,600
-90,000
| -95% | -$1.08M |
|
5824
AngioDynamics
ANGO
$611M
| $41.9K | ﹤0.01% |
3,266
+1,142
| +54% | +$14.1K |
|
5825
CALL
OFS Capital
OFS
$45M
| $41.9K | ﹤0.01% |
8,800
-300
| -3% | -$1.73K |
|
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.