In an unexpected move, Tesla, Inc. (TSLA) founder Elon Musk disclosed in a Monday filing that he has picked up a passive 9.2% stake, or roughly 73.5 million shares in microblogging social media platform Twitter, Inc (TWTR).

Could Musk Be Eyeing More Aggressive Ownership? 

Terming the development as "eye popping," Tesla bull and Wedbush analyst Daniel Ives said it appears that Musk is "laser focused" on Twitter.

This belies earlier expectation that Musk could be looking at building a new social media platform to compete with Twitter and others, the analyst said.

Musk has used Twitter recently to solicit opinions on whether its algorithm should be open source and whether the social media platform is adhering to the principles of free speech. He had even asked whether a new platform is needed.

Wedbush's Ives said: "We would expect this passive stake as just the start of broader conversations with the Twitter board/management that could ultimately lead to an active stake and a potential more aggressive ownership role of Twitter."

The analyst said he would keenly watch if Musk ultimately pursues further conversations with the Twitter board and goes on to build up an active stake above the 10% threshold.

There is no reason to worry about this affecting Musk's focus on Tesla/SpaceX, he said. 

Why Musk's Interest Signals That Twitter Is Relevant: 

Rich Greenfield, partner and analyst at LightShed Partners, said on CNBC's "Squawk Box" that Musk's recent attack on Twitter about its algorithm is an acknowledgment that the social media platform has become so big and so important.

Musk, therefore, believes there should be different algorithms and different ways of information ferreting up to the top, the analyst said. Musk wouldn't care if Twitter were irrelevant or tiny or was not rapidly growing, Greenfield said.

All the same, the analyst said the 9% stake does not give Musk enough power to change the way the company is run in terms of censorship. The development at least gives Twitter shareholders a reason to own the stock, he added.

TSLA, TWTR Price Action: 

Tesla shares were trading 1.22% higher at $1,097 Monday morning and Twitter shares were jumping 20.21% to $47.25.