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 | |
|---|---|---|---|---|---|---|
5626
Annexon
ANNX
$834M
| $51.5K | ﹤0.01% |
+10,268
| New | +$39.3K |
|
5627
CALL
Southern First Bancshares
SFST
$591M
| $51.5K | ﹤0.01% |
1,000
| – | – |
|
5628
CALL
Quanterix
QTRX
$164M
| $51.5K | ﹤0.01% |
8,100
+7,800
| +2,600% | +$48.5K |
|
5629
Ovid Therapeutics
OVID
$414M
| $51.5K | ﹤0.01% |
31,603
-355,909
| -92% | -$548K |
|
5630
CALL
Atossa Therapeutics
ATOS
$20.6M
| $51.5K | ﹤0.01% |
5,820
+5,400
| +1,286% | +$68.3K |
|
5631
Northwest Bancshares
NWBI
$2.3B
| $51.4K | ﹤0.01% |
4,286
-40
| -0.9% | -$487 |
|
5632
Schwab US Broad Market ETF
SCHB
$43.2B
| $51.3K | ﹤0.01% |
+1,956
| New | +$50.9K |
|
5633
CALL
OGE Energy
OGE
$9.78B
| $51.2K | ﹤0.01% |
1,200
+300
| +33% | +$13.4K |
|
|
MAPS
5634
DELISTED
WM TECHNOLOGY INC A
MAPS
| $51.2K | ﹤0.01% |
62,047
+57,385
| +1,231% | +$56.5K |
|
5635
PUT
Vertical Aerospace
EVTL
$158M
| $51.2K | ﹤0.01% |
9,600
-30,500
| -76% | -$155K |
|
5636
Brilliant Earth
BRLT
$17.1M
| $51.1K | ﹤0.01% |
29,225
-31,766
| -52% | -$67.5K |
|
5637
Vericel Corp
VCEL
$2.35B
| $51K | ﹤0.01% |
1,416
+1,370
| +2,978% | +$50.3K |
|
|
UMH
5638
PUT
UMH Properties
UMH
$1.29B
| $50.9K | ﹤0.01% |
3,200
-2,700
| -46% | -$40.5K |
|
|
RWT
5639
PUT
Redwood Trust
RWT
$574M
| $50.9K | ﹤0.01% |
9,200
-6,600
| -42% | -$36.3K |
|
|
CTXRW
5640
CALL
DELISTED
Citius Pharmaceuticals, Inc. Warrant
CTXRW
| $50.8K | ﹤0.01% |
65,400
+56,700
| +652% | +$44.1K |
|
5641
PUT
Humacyte
HUMA
$176M
| $50.8K | ﹤0.01% |
52,900
+30,700
| +138% | +$43.5K |
|
5642
PUT
Atlas Lithium Corp
ATLX
$80.8M
| $50.8K | ﹤0.01% |
12,000
-1,900
| -14% | -$9.57K |
|
|
IMSR
5643
PUT
Terrestrial Energy
IMSR
$520M
| $50.7K | ﹤0.01% |
8,300
-56,900
| -87% | -$761K |
|
5644
PUT
Steris
STE
$22.3B
| $50.7K | ﹤0.01% |
200
-300
| -60% | -$75.3K |
|
5645
CALL
Tiziana Life Sciences
TLSA
$131M
| $50.7K | ﹤0.01% |
34,000
-11,900
| -26% | -$21.4K |
|
|
LADR
5646
CALL
Ladder Capital
LADR
$1.21B
| $50.6K | ﹤0.01% |
4,600
+1,800
| +64% | +$19.5K |
|
5647
LiveRamp
RAMP
$2.3B
| $50.5K | ﹤0.01% |
+1,721
| New | +$49.4K |
|
5648
CALL
Federal Realty Investment Trust
FRT
$10.7B
| $50.4K | ﹤0.01% |
500
| – | – |
|
|
BTM
5649
DELISTED
Bitcoin Depot
BTM
| $50.3K | ﹤0.01% |
+5,569
| New | +$85.4K |
|
5650
CALL
Selective Insurance
SIGI
$5.65B
| $50.2K | ﹤0.01% |
600
-200
| -25% | -$16.1K |
|
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.