Is there going to be a 6th Percy Jackson and the Olympians

Nothing is for sure yet, but it sounds like Rick Riordan is going to start another demigod series, but this time Percy will most likely NOT be the main character. He hasn't said anything for sure yet, but at the end of Book Five there was an author's note that said something like "This is the end of the first Percy Jackson series." Just because he said first leads me to believe that there will be a second. I'm for sure hoping that there will be!

Hope this helped!