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 | |
|---|---|---|---|---|---|---|
1576
NIO
NIO
$11.3B
| $3.36M | ﹤0.01% |
659,692
-420,932
| -39% | -$2.6M |
|
1577
First Horizon
FHN
$12.1B
| $3.36M | ﹤0.01% |
140,744
+41,182
| +41% | +$918K |
|
1578
PUT
PACCAR
PCAR
$69.6B
| $3.36M | ﹤0.01% |
30,700
+3,500
| +13% | +$359K |
|
1579
Citizens Financial Group
CFG
$30.4B
| $3.36M | ﹤0.01% |
57,493
+29,728
| +107% | +$1.6M |
|
1580
SentinelOne
S
$6.22B
| $3.35M | ﹤0.01% |
223,156
+99,257
| +80% | +$1.63M |
|
1581
CALL
Ares Capital
ARCC
$13.5B
| $3.33M | ﹤0.01% |
164,800
+32,900
| +25% | +$664K |
|
1582
CALL
State Street SPDR Portfolio Europe ETF
SPEU
$712M
| $3.32M | ﹤0.01% |
53,900
-22,800
| -30% | -$1.16M |
|
1583
PUT
Bitdeer Technologies
BTDR
$2.81B
| $3.32M | ﹤0.01% |
296,200
-390,600
| -57% | -$6.29M |
|
1584
PUT
2x Long VIX Futures ETF
UVIX
$286M
| $3.31M | ﹤0.01% |
24,085
-3,355
| -12% | -$614K |
|
1585
CALL
Builders FirstSource
BLDR
$7.84B
| $3.31M | ﹤0.01% |
32,200
-4,300
| -12% | -$483K |
|
1586
PUT
BioNTech
BNTX
$22.6B
| $3.31M | ﹤0.01% |
34,800
-73,700
| -68% | -$7.43M |
|
|
METD
1587
PUT
Direxion Daily META Bear 1X ETF
METD
$8.53M
| $3.31M | ﹤0.01% |
312,800
+165,700
| +113% | +$2.63M |
|
1588
Archer Aviation
ACHR
$3.64B
| $3.29M | ﹤0.01% |
437,567
-49,294
| -10% | -$464K |
|
1589
CALL
ProShares UltraShort Health Care
RXD
$3.25M
| $3.28M | ﹤0.01% |
46,550
+14,200
| +44% | +$279K |
|
1590
PUT
TKO Group
TKO
$13.5B
| $3.26M | ﹤0.01% |
15,600
-32,600
| -68% | -$6.34M |
|
|
EXAS
1591
CALL
DELISTED
Exact Sciences
EXAS
| $3.26M | ﹤0.01% |
32,100
-73,100
| -69% | -$5.87M |
|
1592
KraneShares CSI China Internet ETF
KWEB
$5.2B
| $3.25M | ﹤0.01% |
+95,566
| New | +$3.68M |
|
1593
Royal Bank of Canada
RY
$291B
| $3.25M | ﹤0.01% |
+19,071
| New | +$2.93M |
|
1594
CALL
Sempra
SRE
$60.8B
| $3.24M | ﹤0.01% |
36,700
+4,900
| +15% | +$446K |
|
1595
CALL
Huntington Bancshares
HBAN
$35.1B
| $3.24M | ﹤0.01% |
186,700
-10,700
| -5% | -$176K |
|
1596
PUT
Plug Power
PLUG
$2.92B
| $3.24M | ﹤0.01% |
1,643,200
-219,100
| -12% | -$572K |
|
1597
CALL
Murphy USA
MUSA
$11.3B
| $3.23M | ﹤0.01% |
8,000
+900
| +13% | +$345K |
|
|
JMIA
1598
Jumia Technologies
JMIA
$726M
| $3.23M | ﹤0.01% |
258,418
-3,530
| -1% | -$40.8K |
|
1599
CALL
DHT Holdings
DHT
$2.97B
| $3.21M | ﹤0.01% |
263,300
+160,500
| +156% | +$2.02M |
|
1600
PUT
Wave Life Sciences
WVE
$1.12B
| $3.21M | ﹤0.01% |
189,100
+173,200
| +1,089% | +$1.76M |
|
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.