DONALD SMITH & CO., INC. reported MATTSON TECHNOLOGY com (MTSN) in 26 quarterly 13F filings .
This page tracks quarterly shares, estimated market value, portfolio weight, filing dates, and disclosure-aligned stock prices directly from SEC EDGAR 13F filings. Older history is available after unlock; the visible window still shows the most recent pattern.
This page is designed to answer the real investor question behind a 13F filing: how meaningful was DONALD SMITH & CO., INC.'s position in MATTSON TECHNOLOGY com, and how did that conviction change over time? You can read the holding window, peak weight, latest reported size, disclosure timing, and quarter-by-quarter changes without piecing the story together from raw SEC rows.
See the most recent quarter where the fund disclosed this position.
Peak weight helps separate a token disclosure from a real conviction holding the fund genuinely cared about.
Longer holding windows often tell a very different story from short-lived tactical trades or one-quarter experiments.
Knowing that a fund owned a stock is useful. Knowing whether it was a 0.20% placeholder or a true high-conviction position is where the signal actually starts.
As of 2016 Q1 β sorted by position size
These are the practical questions this page is built to answer before you even open the full history table.
DONALD SMITH & CO., INC. reported MTSN across 0 quarterly 13F filings.
This page shows the quarter-by-quarter portfolio weight history for MTSN in DONALD SMITH & CO., INC..
The most recent filing on this page is 2016 Q1, when DONALD SMITH & CO., INC. reported 3,029,460 shares, equal to 0.31% of portfolio, with an estimated market value of $11.1M.
The chart compares DONALD SMITH & CO., INC.'s quarterly MTSN portfolio weight with the stock's indexed share price, so you can see whether the fund was building, trimming, or holding the position as price moved.