PALO ALTO (CBS SF) – Electric car maker Tesla has a new product in the works, but it’s not a new model, according to CEO Elon Musk.

It’s not clear what Musk is hinting at, but it sent shares of the Palo Alto based car maker climbing. The SpaceX chief and PayPal founder has become must-follow on Twitter for tech sector investors.

Earlier this month Tesla shares jumped after Musk said he would “end range anxiety” for Model S drivers by providing a software update. Sending the shares up several dollars.

During trading Monday, shares jumped over two percent (about $4) immediately following the Tweet.