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 | |
|---|---|---|---|---|---|---|
6951
PUT
VEON
VEON
$3.66B
| $10.5K | ﹤0.01% |
200
-800
| -80% | -$40.5K |
|
6952
PUT
ProFrac Holding
ACDC
$671M
| $10.5K | ﹤0.01% |
2,700
-5,300
| -66% | -$21.6K |
|
|
ADAM
6953
Adamas Trust
ADAM
$803M
| $10.5K | ﹤0.01% |
+1,437
| New | +$10.2K |
|
6954
CALL
Brixmor Property Group
BRX
$9.67B
| $10.5K | ﹤0.01% |
400
-12,600
| -97% | -$333K |
|
6955
WhiteHorse Finance
WHF
$137M
| $10.5K | ﹤0.01% |
+1,509
| New | +$10.7K |
|
6956
PUT
News Corp Class B
NWS
$17.2B
| $10.4K | ﹤0.01% |
400
-9,500
| -96% | -$283K |
|
6957
Global X S&P 500 Covered Call ETF
XYLD
$3.22B
| $10.4K | ﹤0.01% |
257
-159
| -38% | -$6.36K |
|
6958
iShares US Transportation ETF
IYT
$2.26B
| $10.4K | ﹤0.01% |
+140
| New | +$10.2K |
|
|
6959
PUT
WhiteHorse Finance
WHF
$137M
| $10.4K | ﹤0.01% |
+1,500
| New | +$10.7K |
|
|
PTRN
6960
Pattern Group Inc
PTRN
$4.23B
| $10.4K | ﹤0.01% |
+903
| New | +$13.1K |
|
6961
CALL
Korro Bio
KRRO
$151M
| $10.4K | ﹤0.01% |
+1,300
| New | +$30.4K |
|
6962
PUT
RPM International
RPM
$13.8B
| $10.4K | ﹤0.01% |
+100
| New | +$10.8K |
|
6963
BancFirst
BANF
$3.77B
| $10.4K | ﹤0.01% |
+98
| New | +$11.1K |
|
6964
CALL
Custom Truck One Source
CTOS
$2.26B
| $10.4K | ﹤0.01% |
1,800
-9,300
| -84% | -$56.8K |
|
6965
Travelzoo
TZOO
$73.3M
| $10.4K | ﹤0.01% |
1,456
+1,379
| +1,791% | +$11.2K |
|
6966
CALL
BARK
BARK
$77.6M
| $10.4K | ﹤0.01% |
860
+700
| +438% | +$10.4K |
|
6967
PUT
Personalis
PSNL
$1.31B
| $10.3K | ﹤0.01% |
1,300
-32,400
| -96% | -$283K |
|
6968
PUT
TFI International
TFII
$11B
| $10.3K | ﹤0.01% |
100
-900
| -90% | -$83.8K |
|
|
VBNK
6969
VersaBank
VBNK
$625M
| $10.3K | ﹤0.01% |
+689
| New | +$8.68K |
|
6970
PUT
Alpha Architect US Quantitative Value ETF
QVAL
$587M
| $10.3K | ﹤0.01% |
+200
| New | +$9.49K |
|
6971
Direxion Daily Consumer Discretionary Bull 3X ETF
WANT
$14.9M
| $10.2K | ﹤0.01% |
204
+172
| +538% | +$8.63K |
|
6972
Veeco
VECO
$2.95B
| $10.2K | ﹤0.01% |
357
+19
| +6% | +$563 |
|
6973
iShares 25+ Year Treasury STRIPS Bond ETF
GOVZ
$258M
| $10.2K | ﹤0.01% |
276
-2,722
| -91% | -$106K |
|
|
RAPT
6974
PUT
DELISTED
RAPT Therapeutics
RAPT
| $10.2K | ﹤0.01% |
300
| – | – |
|
6975
CALL
FTAI Infrastructure
FIP
$473M
| $10.1K | ﹤0.01% |
2,200
-4,700
| -68% | -$23.2K |
|
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.