Microsoft Corp (MSFT) took the top spot in Mark Massey's AltaRock Partners portfolio in 2026 Q3, according to the 13F-HR filed with the SEC on November 13, 2026. The stake is 2.64M shares worth about $1.35B at September 30, 2026, 32.15% of the reported portfolio. MSFT ranked 3rd a quarter earlier, at 20.54% of the book.
What did the 2026 Q3 filing report for MSFT?
As of September 30, 2026, from the 13F-HR filed November 13, 2026.
| Value | |
|---|---|
| Portfolio weight | 32.15% |
| Shares | 2.64M |
| Reported value | $1.35B |
| Rank in portfolio | 1st of 8 |
| Rank a quarter earlier | 3rd |
| Largest holding a quarter earlier | AMZN at 32.21% |
| Next largest holding now | AMZN at 28.53% |
How did MSFT become the largest holding?
Mark Massey added 13% to the MSFT share count in 2026 Q3. AMZN, the largest holding a quarter earlier at 32.21%, was trimmed to 28.53%, now 2nd. The next largest holding now is AMZN at 28.53%.
Where does MSFT sit in the Mark Massey portfolio?
MSFT is the largest of 8 stock positions in the Mark Massey portfolio at 32.15%, above the fund's average stock position of 13%. The MSFT addition was the 2nd largest of the quarter's 7 position changes by percent change to portfolio. Across the 2026 Q3 portfolio, Mark Massey reported 8 stock positions, with no position opened or closed. The total portfolio value is about $4.21B, down 1% from the prior quarter.
How long has Mark Massey held MSFT?
Mark Massey first reported MSFT in the quarter ended June 30, 2021. The current weight is the highest the fund has reported for the name. Last quarter the fund added to the position by 25%. Every reported trade is on the Mark Massey MSFT trade history page.
Did other funds buy or sell MSFT in 2026 Q3?
Among the other tracked funds that had filed for 2026 Q3 as of November 13, 2026, 17 hold MSFT. One other tracked fund sold out of it. The largest buyers of MSFT this quarter were Donald Yacktman, Parnassus Endeavor Fund and Richard Pzena. The largest sellers were Lewis Sanders, Polen Capital Management and Nathaniel Simons. Every tracked holder of MSFT is on the MSFT ownership page.
FAQ
What is the largest holding in the Mark Massey portfolio?
MSFT is the largest holding in the Mark Massey portfolio as of 2026 Q3, at 32.15% of the reported value.
What was the largest holding of Mark Massey a quarter earlier?
AMZN, at 32.21% of the book. AMZN, the largest holding a quarter earlier at 32.21%, was trimmed to 28.53%, now 2nd.
How did MSFT become the largest holding of Mark Massey?
MSFT ranked 3rd a quarter earlier, at 20.54% of the book. Mark Massey added 13% to the MSFT share count in 2026 Q3. AMZN, the largest holding a quarter earlier at 32.21%, was trimmed to 28.53%, now 2nd.
How many MSFT shares does Mark Massey hold?
Mark Massey holds 2.64M shares of MSFT, worth about $1.35B at September 30, 2026 prices.