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 | |
|---|---|---|---|---|---|---|
3876
Danaos Corp
DAC
$2.52B
| $283K | ﹤0.01% |
3,010
-3,838
| -56% | -$354K |
|
|
AEVA
3877
Aeva Technologies
AEVA
$954M
| $283K | ﹤0.01% |
21,331
+20,973
| +5,858% | +$299K |
|
3878
PUT
ICICI Bank
IBN
$108B
| $283K | ﹤0.01% |
9,500
-1,800
| -16% | -$55.2K |
|
|
TRON
3879
CALL
Tron Inc
TRON
$707M
| $282K | ﹤0.01% |
227,800
+75,000
| +49% | +$169K |
|
3880
CALL
NRX Pharmaceuticals
NRXP
$144M
| $282K | ﹤0.01% |
104,200
+29,100
| +39% | +$78.1K |
|
3881
PUT
Cerence
CRNC
$361M
| $282K | ﹤0.01% |
26,400
-13,300
| -34% | -$146K |
|
3882
CALL
AGCO
AGCO
$8.4B
| $282K | ﹤0.01% |
2,700
-2,200
| -45% | -$234K |
|
3883
Kaspi.kz JSC
KSPI
$16.7B
| $282K | ﹤0.01% |
3,604
+1,177
| +48% | +$89K |
|
|
MBX
3884
MBX Biosciences
MBX
$2.98B
| $281K | ﹤0.01% |
+8,925
| New | +$217K |
|
|
GRFS
3885
CALL
Grifois
GRFS
$5.58B
| $281K | ﹤0.01% |
30,100
+2,300
| +8% | +$20.9K |
|
3886
PepGen
PEPG
$121M
| $281K | ﹤0.01% |
+43,194
| New | +$224K |
|
3887
PUT
Vanguard FTSE Developed Markets ETF
VEA
$223B
| $281K | ﹤0.01% |
4,500
-3,300
| -42% | -$202K |
|
3888
Global Ship Lease
GSL
$1.56B
| $280K | ﹤0.01% |
8,005
-7,231
| -47% | -$235K |
|
3889
PUT
1-800-Flowers.com
FLWS
$255M
| $280K | ﹤0.01% |
71,300
+38,700
| +119% | +$152K |
|
|
BRR
3890
CALL
ProCap Financial Inc
BRR
$153M
| $280K | ﹤0.01% |
79,300
+48,000
| +153% | +$383K |
|
3891
Warner Music
WMG
$15.5B
| $279K | ﹤0.01% |
+9,103
| New | +$278K |
|
3892
VanEck Vietnam ETF
VNM
$480M
| $278K | ﹤0.01% |
14,573
-1,117
| -7% | -$20.3K |
|
3893
PUT
Acadia Pharmaceuticals
ACAD
$4.46B
| $278K | ﹤0.01% |
10,400
-21,100
| -67% | -$504K |
|
3894
Atlas Energy Solutions
AESI
$1.33B
| $278K | ﹤0.01% |
29,474
+24,645
| +510% | +$249K |
|
|
HOOW
3895
Roundhill HOOD WeeklyPay ETF
HOOW
$103M
| $278K | ﹤0.01% |
+5,843
| New | +$373K |
|
3896
CALL
Kimbell Royalty Partners
KRP
$1.46B
| $278K | ﹤0.01% |
23,600
-163,400
| -87% | -$2.09M |
|
3897
CALL
Wabtec
WAB
$50B
| $277K | ﹤0.01% |
1,300
+500
| +63% | +$103K |
|
3898
PUT
Cemex
CX
$17B
| $277K | ﹤0.01% |
24,100
+3,400
| +16% | +$35.2K |
|
3899
CALL
Dime Commercial Bancshares
DCOM
$1.8B
| $277K | ﹤0.01% |
9,200
+6,900
| +300% | +$199K |
|
|
3900
CALL
Global Ship Lease
GSL
$1.56B
| $277K | ﹤0.01% |
7,900
-2,100
| -21% | -$68.2K |
|
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.