In what may be considered a big boost to Instagram’s future, the amount of Vine videos shared on Twitter has dropped dramatically since Facebook’s Instagram launched a video feature last week,according to social media analytics site Topsy.

In a grand event at Facebook’s headquarters last Thursday, Instagram co-founder Kevin Systrom announced that his app, which was sold to Facebook for $1 billion in cash and stock in 2012, is “the same Instagram that we know and love … but (now) it moves.” 

What was once called the “Instagram for video,” Vine has serious head-to-head competition in Instagram after the photo-sharing application pivoted and allowed its 130 million users to share 15-second clips.

Vine, acquired by Twitter in 2012 for a reported $30 million, lets its nearly 20 million users share six-second videos and has grown increasingly popular since its launch in January.

Taking a look at a Topsy chart that maps shares on Twitter of Instagram photos and videos versus Vine videos, the change is drastic. 

After reaching a peak of nearly 2.9 million shares on June 15, Vine shares on Twitter dropped sharply to 1.35 million—more than a 50 percent decrease—on June 21, just a day after Instagram video was launched.

Strikingly, on that very same day Vine saw the spike, Instagram shares on Twitter surpassed Vine shares on Twitter, perhaps signaling that Vine users fled the platform to embrace the now-multi-purpose Instagram. (On May 30, shortly after Vine was released on Android devices, 

Vine was applauded when its shares on Twitter finally surpassed that of Instagram’s.)

It’s no secret that Facebook and Twitter—and more lately, respective subsidiaries Instagram and Vine—are competing for top dog in the social sharing world.

It’s been well documented that the tech companies will not allow one another to feed off each other’s data.

But shutting a rival out is a defensive move, and now, it appears that Facebook and Twitter are playing offense: Instagram moved quickly into Vine’s videospace, so Vine, after hearing rumors this feature was coming, decided to tease new features, encourage Twitter users in an email to download Vine, and granted an informative interview to the New York Times. All, perhaps, in an effort to go all-in against its new rival Instagram.

Facebook and Twitter did not immediately respond for comment on the shift in social sharing.

Facebook investors, hungry for some good news, may take solace that there is now a strong indicator that the social media giant has the leg-up in the battle over social video.