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 | |
|---|---|---|---|---|---|---|
6626
PUT
Horizon Bancorp
HBNC
$1.04B
| $17K | ﹤0.01% |
1,000
-1,400
| -58% | -$23.2K |
|
6627
PUT
Inter&Co
INTR
$2.47B
| $17K | ﹤0.01% |
2,000
-3,900
| -66% | -$34.5K |
|
6628
CALL
Midland States Bancorp
MSBI
$699M
| $16.9K | ﹤0.01% |
800
+300
| +60% | +$5.3K |
|
6629
CALL
NRC Health Common Stock
NRC
$432M
| $16.9K | ﹤0.01% |
900
+200
| +29% | +$3.02K |
|
6630
PUT
Crescent Capital BDC
CCAP
$403M
| $16.9K | ﹤0.01% |
1,200
-2,700
| -69% | -$38.4K |
|
6631
Vanguard Intermediate-Term Corporate Bond ETF
VCIT
$66.2B
| $16.8K | ﹤0.01% |
+201
| New | +$16.9K |
|
6632
PUT
Timken Company
TKR
$9.56B
| $16.8K | ﹤0.01% |
200
-100
| -33% | -$7.96K |
|
6633
PUT
Angi Inc
ANGI
$229M
| $16.8K | ﹤0.01% |
1,300
+500
| +63% | +$6.44K |
|
6634
PUT
Franklin Covey
FC
$242M
| $16.8K | ﹤0.01% |
1,000
-100
| -9% | -$1.68K |
|
|
AISP
6635
PUT
Airship AI Holdings
AISP
$60.3M
| $16.8K | ﹤0.01% |
5,800
+3,100
| +115% | +$12.8K |
|
6636
PUT
Solana Company
HSDT
$96.3M
| $16.8K | ﹤0.01% |
+5,800
| New | +$38.3K |
|
6637
PUT
Gain Therapeutics
GANX
$71.7M
| $16.7K | ﹤0.01% |
+5,200
| New | +$13.9K |
|
6638
CALL
PJT Partners
PJT
$4.3B
| $16.7K | ﹤0.01% |
100
| – | – |
|
6639
PUT
Towne Bank
TOWN
$3.46B
| $16.7K | ﹤0.01% |
500
| – | – |
|
6640
PUT
Twin Disc
TWIN
$329M
| $16.7K | ﹤0.01% |
1,000
| – | – |
|
6641
CALL
GrowGeneration
GRWG
$86.5M
| $16.6K | ﹤0.01% |
11,100
-3,000
| -21% | -$4.92K |
|
6642
PUT
Azenta
AZTA
$1.3B
| $16.6K | ﹤0.01% |
500
+100
| +25% | +$3.27K |
|
|
OPTU
6643
Optimum Communications Inc
OPTU
$298M
| $16.6K | ﹤0.01% |
+10,075
| New | +$20.5K |
|
|
SKE
6644
CALL
Skeena Resources
SKE
$3.3B
| $16.6K | ﹤0.01% |
700
-31,600
| -98% | -$623K |
|
6645
CALL
Kaltura
KLTR
$206M
| $16.6K | ﹤0.01% |
+10,100
| New | +$16K |
|
6646
iShares MSCI Singapore ETF
EWS
$1.04B
| $16.5K | ﹤0.01% |
+601
| New | +$16.9K |
|
6647
MSC Industrial Direct
MSM
$6.89B
| $16.5K | ﹤0.01% |
+196
| New | +$17K |
|
|
DOJE
6648
REX-Osprey DOGE ETF
DOJE
$12.1M
| $16.5K | ﹤0.01% |
+1,509
| New | +$24.2K |
|
|
KW
6649
PUT
DELISTED
Kennedy-Wilson Holdings
KW
| $16.4K | ﹤0.01% |
1,700
-4,600
| -73% | -$41.2K |
|
6650
iShares MSCI Intl Momentum Factor ETF
IMTM
$4.13B
| $16.4K | ﹤0.01% |
341
+31
| +10% | +$1.49K |
|
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.