In many of the markets covered by our Stock Screener, the table not only contains the primary listed companies for that market, but might also contain companies that are listed on that market as an additional or optional placement.
If you want to filter out these additional symbols, we have introduced a new “Primary Listing” filter. You can find it in the filters menu located in the right corner.
For example, AAPL’s primary listing is on the U.S. Nasdaq exchange. However, the company also lists its ticker on other international exchanges, such as the Italian market.
If you want to see all symbols for the Italian market, this filter should be disabled. To see them, select the Italian market in the Stock Screener, open filters and uncheck the “Primary Listing” one.
If you only want to see symbols that have their main listing in the Italian market, you can enable the  “Primary Listing” filter, and exclude optional additions like AAPL from your list.
This filter is included in all default filter sets, e.g. Most Capitalized, Volume leaders, etc. It doesn’t affect custom filter sets, you can add it manually from the list with all other screener filters.