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 | |
|---|---|---|---|---|---|---|
5076
PUT
Vanguard Total Bond Market
BND
$157B
| $92.7K | ﹤0.01% |
1,300
-5,200
| -80% | -$387K |
|
5077
Church & Dwight Co
CHD
$23.4B
| $92.4K | ﹤0.01% |
1,102
-10,635
| -91% | -$908K |
|
5078
abrdn Bloomberg All Commodity Strategy K-1 Free ETF
BCI
$2.95B
| $92.3K | ﹤0.01% |
4,728
+3,528
| +294% | +$78.4K |
|
5079
Roundhill Bitcoin Covered Call Strategy ETF
YBTC
$125M
| $92.3K | ﹤0.01% |
+3,245
| New | +$115K |
|
5080
GoodRx Holdings
GDRX
$1.04B
| $92.3K | ﹤0.01% |
34,065
-394,276
| -92% | -$1.29M |
|
5081
CALL
Usana Health Sciences
USNA
$408M
| $92.3K | ﹤0.01% |
4,700
-400
| -8% | -$8.3K |
|
|
MTLS
5082
Materialise
MTLS
$368M
| $92.2K | ﹤0.01% |
16,615
+1,646
| +11% | +$9.74K |
|
5083
Morningstar
MORN
$7.22B
| $92.1K | ﹤0.01% |
424
+364
| +607% | +$78.8K |
|
5084
ARK Web x.0 ETF
ARKW
$1.63B
| $91.4K | ﹤0.01% |
+619
| New | +$100K |
|
5085
PUT
Vestis
VSTS
$1.91B
| $91.4K | ﹤0.01% |
13,700
+13,200
| +2,640% | +$77K |
|
5086
CALL
SLR Investment Corp
SLRC
$686M
| $91.2K | ﹤0.01% |
5,900
+5,400
| +1,080% | +$82.3K |
|
5087
PUT
Fabrinet
FN
$15.6B
| $91.1K | ﹤0.01% |
200
-700
| -78% | -$305K |
|
5088
PUT
Microvision
MVIS
$93.2M
| $91K | ﹤0.01% |
109,900
-10,100
| -8% | -$10.7K |
|
5089
CALL
CMS Energy
CMS
$22.6B
| $90.9K | ﹤0.01% |
1,300
-8,600
| -87% | -$625K |
|
5090
PUT
Evolent Health
EVH
$348M
| $90.8K | ﹤0.01% |
22,700
+11,900
| +110% | +$66.2K |
|
|
JOYY
5091
CALL
JOYY Inc
JOYY
$3.71B
| $90.7K | ﹤0.01% |
1,400
-27,400
| -95% | -$1.67M |
|
5092
Fulcrum Therapeutics
FULC
$239M
| $90.6K | ﹤0.01% |
8,014
-4,786
| -37% | -$48.7K |
|
5093
CALL
Target Hospitality
TH
$1.51B
| $90.5K | ﹤0.01% |
11,300
-47,400
| -81% | -$360K |
|
5094
Inhibrx
INBX
$1.2B
| $90.5K | ﹤0.01% |
+1,145
| New | +$78K |
|
|
NLOP
5095
CALL
Net Lease Office Properties
NLOP
$173M
| $90.3K | ﹤0.01% |
3,500
-2,100
| -38% | -$59.4K |
|
5096
CALL
Intellicheck
IDN
$73.1M
| $90.2K | ﹤0.01% |
13,500
+12,600
| +1,400% | +$71.1K |
|
|
NB
5097
PUT
NioCorp Developments
NB
$619M
| $90.1K | ﹤0.01% |
17,000
-39,200
| -70% | -$270K |
|
5098
PUT
O-I Glass
OI
$1.1B
| $90K | ﹤0.01% |
6,100
+3,000
| +97% | +$39.7K |
|
|
UDMY
5099
DELISTED
Udemy
UDMY
| $89.9K | ﹤0.01% |
+15,369
| New | +$89.6K |
|
5100
Relmada Therapeutics
RLMD
$557M
| $89.9K | ﹤0.01% |
18,611
-34,471
| -65% | -$115K |
|
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.