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 | |
|---|---|---|---|---|---|---|
726
PUT
XPeng
XPEV
$12.3B
| $12.8M | 0.01% |
630,800
-232,200
| -27% | -$5.04M |
|
727
PUT
CRH
CRH
$66.9B
| $12.8M | 0.01% |
102,400
+50,700
| +98% | +$6.04M |
|
728
CALL
Chubb
CB
$133B
| $12.8M | 0.01% |
40,900
+12,100
| +42% | +$3.54M |
|
729
CALL
FedEx
FDX
$75.9B
| $12.7M | 0.01% |
44,100
-52,500
| -54% | -$13.8M |
|
730
ProShares Ultra Silver
AGQ
$1.22B
| $12.6M | 0.01% |
81,434
-26,947
| -25% | -$2.78M |
|
731
CALL
Li Auto
LI
$12B
| $12.6M | 0.01% |
745,600
+96,700
| +15% | +$1.92M |
|
732
CALL
Ciena
CIEN
$56.2B
| $12.5M | 0.01% |
53,600
-109,900
| -67% | -$21.3M |
|
733
PUT
DexCom
DXCM
$27.6B
| $12.5M | 0.01% |
187,800
-4,900
| -3% | -$317K |
|
734
CALL
Alcoa
AA
$12.2B
| $12.4M | 0.01% |
233,800
+46,500
| +25% | +$1.9M |
|
735
PUT
Hilton Worldwide
HLT
$73.8B
| $12.4M | 0.01% |
43,200
-14,800
| -26% | -$4.03M |
|
|
UCD
736
PUT
DELISTED
PROSHARES ULTRA BLOOMBERG COMMODITY
UCD
| $12.3M | 0.01% |
137,900
+102,800
| +293% | +$9.2M |
|
737
CALL
NXP Semiconductors
NXPI
$70.4B
| $12.3M | 0.01% |
56,800
+15,200
| +37% | +$3.26M |
|
738
Snap
SNAP
$7.52B
| $12.3M | 0.01% |
1,527,426
+456,916
| +43% | +$3.61M |
|
739
CALL
PureCycle Technologies
PCT
$1.26B
| $12.3M | 0.01% |
1,427,300
+858,900
| +151% | +$9.12M |
|
740
PUT
Centene
CNC
$32.5B
| $12.3M | 0.01% |
297,800
-4,700
| -2% | -$176K |
|
|
SHNY
741
PUT
DELISTED
Direxion Daily Silver Miners Index Bull 2X Shares
SHNY
| $12.2M | 0.01% |
343,200
-118,100
| -26% | -$4.21M |
|
742
CALL
Vanguard Emerging Markets Government Bond ETF
VWOB
$6.17B
| $12.2M | 0.01% |
85,900
+31,200
| +57% | +$2.1M |
|
|
743
CALL
CRH
CRH
$66.9B
| $12.2M | 0.01% |
97,800
+34,700
| +55% | +$4.13M |
|
744
Alphabet (Google) Class A
GOOGL
$4.17T
| $12.1M | 0.01% |
38,768
-232,207
| -86% | -$66.3M |
|
745
PUT
SiriusXM
SIRI
$10B
| $12.1M | 0.01% |
613,000
-18,800
| -3% | -$404K |
|
746
CALL
SoundHound AI
SOUN
$2.81B
| $12.1M | 0.01% |
1,215,400
-1,212,200
| -50% | -$17.4M |
|
747
PUT
Electronic Arts
EA
$52.4B
| $12.1M | 0.01% |
59,300
-44,900
| -43% | -$9.06M |
|
748
PUT
Vertex Pharmaceuticals
VRTX
$120B
| $12.1M | 0.01% |
26,700
+5,700
| +27% | +$2.46M |
|
749
CALL
Planet Labs
PL
$8.05B
| $12.1M | 0.01% |
613,700
-120,400
| -16% | -$1.73M |
|
750
Advanced Micro Devices
AMD
$901B
| $12.1M | 0.01% |
56,475
+46,200
| +450% | +$10.4M |
|
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.