WESTFIELD CAPITAL MANAGEMENT CO LP
Top Portfolio Positions
243 positions ·
$23,810,970,015 total
· as of Mar 31, 2026
| Ticker | Company | Shares | Value (USD) | % of Portfolio | Open |
|---|---|---|---|---|---|
| NVDA |
Nvidia Corp
Technology
|
6,317,039 | $1,101,691,601 | 4.63% | |
| ASND |
Ascendis Pharma A/S
Healthcare
|
4,813,440 | $1,100,978,131 | 4.62% | |
| FIX |
Comfort Systems USA Inc
Industrials
|
620,915 | $856,235,575 | 3.60% | |
| AAPL |
Apple Inc.
Technology
|
3,133,113 | $795,152,748 | 3.34% | |
| FTAI |
FTAI Aviation Ltd.
Industrials
|
2,848,227 | $697,815,615 | 2.93% | |
| MSFT |
Microsoft Corp
Technology
|
1,649,513 | $610,600,227 | 2.56% | |
| GOOGL |
Alphabet Inc.
Communication Services
|
2,026,744 | $582,810,504 | 2.45% | |
| HWM |
Howmet Aerospace Inc.
Industrials
|
2,289,697 | $527,683,570 | 2.22% | |
| VRT |
Vertiv Holdings Co
Industrials
|
1,921,696 | $481,538,583 | 2.02% | |
| AMZN |
Amazon Com Inc
Consumer Cyclical
|
2,279,654 | $474,783,538 | 1.99% |
Portfolio Trend
25 quarters · across all stocks
Holdings in ONTO
Shares Held
Position Value (USD)
8 quarters on record
| Report Date | Value (USD) | Shares | Type | Discretion | Filed | |
|---|---|---|---|---|---|---|
| 2026-03-31 | $67,049,687 | 326,960 | Shares | Sole | 2026-05-11 | |
| 2025-12-31 | $76,259,324 | 483,082 | Shares | Sole | 2026-02-11 | |
| 2025-09-30 | $61,318,766 | 474,530 | Shares | Sole | 2025-11-12 | |
| 2025-06-30 | $35,432,889 | 351,064 | Shares | Sole | 2025-08-12 | |
| 2025-03-31 | $24,700,698 | 203,566 | Shares | Sole | 2025-05-09 | |
| 2024-12-31 | $46,698,100 | 280,183 | Shares | Sole | 2025-02-11 | |
| 2023-06-30 | $26,345,397 | 226,199 | Shares | Sole | 2023-08-11 | |
| 2023-03-31 | $26,540,902 | 302,013 | Shares | Sole | 2023-05-12 | |
| No 13F history on record for this holder in this stock. | ||||||