Preloaded Watchlists are ready-to-use lists of common groupings (like the components of the S&P 100, the Dow Industrials, and so forth) which you can fetch with a mouse click.
To use it, just click the Watch Lists link and choose Preloaded Watchlists:
Premium users will recognize the dialog box that comes up next, since it resembles the Published Watchlists feature. You can see the lists, their descriptions, and Subscribe or Unsubscribe to any of them by choosing the corresponding dropdown.
Once you subscribe to something, it will appear on your watch lists module.
You can obviously scroll through the charts in these lists, but if you want to monkey around with them (add symbols, delete symbols, etc.) the best thing to do would be to COPY the symbols from a preloaded list into a new list of your own.
It should also be noted there is an absolutely treasure chest of international index data – – numbering over 700 symbols – – accessible via this feature.