Valve themselves has never hinted that there is going to be a Portal 3 so why are the fans so convince that there will be another sequel to the game. Well, the way Valve ending the last game was pretty convincing.
The mysteries ending where Chell was placed in a field with a companion cube suggest that there might be more. Of course, the developers could have made it that way so that they can pick up the game in the future if they wanted to. That does not mean that future is now.
Some fans are convinced that Valve will announce the Portal 3 game this year but we don’t think you should get your hopes up high just yet since we are already close to the end of the year and so far, we have not heard of any Portal 3 news.
We do not know what it is with Valve and the third installment of their games but it does feel like they can never get to the third installment. Half-Life 2, Left 4 Dead 2 and Portal 2 are great examples.