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 | |
|---|---|---|---|---|---|---|
2576
Eaton
ETN
$157B
| $1.06M | ﹤0.01% |
3,322
-3,678
| -53% | -$1.3M |
|
2577
CALL
Boyd Gaming
BYD
$6.47B
| $1.06M | ﹤0.01% |
12,400
-32,000
| -72% | -$2.64M |
|
2578
PUT
Zura Bio
ZURA
$497M
| $1.06M | ﹤0.01% |
201,400
+198,200
| +6,194% | +$784K |
|
2579
ProShares Short VIX Short-Term Futures ETF
SVXY
$220M
| $1.05M | ﹤0.01% |
19,041
+11,358
| +148% | +$574K |
|
2580
Vicor
VICR
$9.62B
| $1.05M | ﹤0.01% |
9,596
+6,702
| +232% | +$570K |
|
|
KYIV
2581
CALL
Kyivstar Group
KYIV
$3.09B
| $1.05M | ﹤0.01% |
81,000
+34,500
| +74% | +$454K |
|
2582
PUT
Sony
SONY
$123B
| $1.05M | ﹤0.01% |
157,200
+29,800
| +23% | +$837K |
|
2583
CALL
Genius Sports
GENI
$1.73B
| $1.05M | ﹤0.01% |
95,100
-69,200
| -42% | -$755K |
|
2584
PUT
Ambev
ABEV
$47.3B
| $1.05M | ﹤0.01% |
423,800
+700
| +0.2% | +$1.67K |
|
2585
PUT
Designer Brands
DBI
$277M
| $1.05M | ﹤0.01% |
140,800
+126,300
| +871% | +$607K |
|
|
CGC
2586
PUT
Canopy Growth
CGC
$375M
| $1.04M | ﹤0.01% |
940,900
+315,000
| +50% | +$405K |
|
2587
PUT
Global Ship Lease
GSL
$1.57B
| $1.04M | ﹤0.01% |
29,800
-3,200
| -10% | -$104K |
|
2588
CALL
NovoCure
NVCR
$2.04B
| $1.04M | ﹤0.01% |
80,600
-27,300
| -25% | -$350K |
|
2589
PUT
PBF Energy
PBF
$7.29B
| $1.04M | ﹤0.01% |
38,400
+27,800
| +262% | +$890K |
|
2590
CALL
News Corp Class B
NWS
$16.4B
| $1.04M | ﹤0.01% |
39,800
-12,300
| -24% | -$367K |
|
|
Q
2591
CALL
Qnity Electronics Inc
Q
$28.3B
| $1.04M | ﹤0.01% |
+12,700
| New | +$1.08M |
|
|
EU
2592
CALL
enCore Energy
EU
$221M
| $1.03M | ﹤0.01% |
416,300
+357,900
| +613% | +$1.02M |
|
2593
CALL
Kopin
KOPN
$663M
| $1.03M | ﹤0.01% |
441,100
+54,000
| +14% | +$156K |
|
2594
CALL
Parsons
PSN
$6.28B
| $1.03M | ﹤0.01% |
16,700
+2,300
| +16% | +$180K |
|
2595
TAL Education Group
TAL
$5.71B
| $1.02M | ﹤0.01% |
93,939
+20,332
| +28% | +$231K |
|
2596
Kinder Morgan
KMI
$73.1B
| $1.02M | ﹤0.01% |
+37,278
| New | +$1.01M |
|
2597
CALL
InMode
INMD
$872M
| $1.02M | ﹤0.01% |
69,600
+7,700
| +12% | +$113K |
|
2598
Ametek
AME
$55.5B
| $1.02M | ﹤0.01% |
+4,944
| New | +$962K |
|
2599
iShares US Aerospace & Defense ETF
ITA
$14.2B
| $1.01M | ﹤0.01% |
4,727
+340
| +8% | +$71.2K |
|
|
CMBT
2600
CALL
CMB.TECH NV
CMBT
$4.57B
| $1.01M | ﹤0.01% |
105,100
+13,200
| +14% | +$128K |
|
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.