If you use Google Finance to keep track of your investments using the portfolio feature, you're soon going to be disappointed. The platform is under renovation and will presumably get a number of design and functional changes. The only thing we know for sure, however, is that the My Portfolio page will no longer be available come mid-November.
The changes are apparently to make the service "more accessible and user-friendly for a wider audience." According to the deprecation information on the help page, you'll still be able to follow stocks in the new interface, and those currently in your portfolio will be automatically migrated. It will be devoid of personalized information, though, so it won't keep track of your number of shares, cost basis, or how much they've gained or lost.
You'll still be able to follow industry news and market trends with Google Finance, too, and who knows what other new features (if any) will be introduced. As for your portfolio, you're going to have to find an alternative service ahead of the mid-November retirement date. In the meantime, you can download your portfolio information as a spreadsheet or OFX file for easy migration once you've decided on a new home for it.