Harry Potter spin-off to be a trilogy

Warner Bros. is planning another big, blockbuster trilogy with the Harry Potter spin-off by J.K. Rowling. Fantastic Beasts and Where to Find Them will receive the trilogy treatment by the studio, revealed by WB CEO Kevin Tsujihara. Early in the planning staged Tsujihara wanted it to be a new franchise but was hesitant to give details.

Rowling was persuaded to expand on the 2001 Hogwarts textbook, Fantastic Beasts and Where to Find Them, into a film adaptation and credits Tsujihara for the push. She states to this day that it wouldn't be happening if it wasn't for him.
Fantastic Beasts will be set in New York seven decades prior to the Potter series. It follows magizoologist Newt Scamander and is not considered either a prequel or sequel, but an extension of the wizard universe.

Personally, I think WB is hurting financially when it comes to blockbusters and figured trying to revive the HP world was the best way to do it. Rowling has no life outside of HP either, so I guess it makes sense.