It's Vote Leave which is fuelling the biggest discussion, with almost twice as many mentions of Leave and other related hashtags as Remain related tweets.]
That's according to data from social media monitoring firm Brandwatch, which has scanned millions of tweets over the past month in the run up to the vote to shed light on the debate. In total, there have been more than five million votes on subject - an almost unprecedented volume on a UK issue.
The top hashtags related to the referendum are #Brexit, #VoteLeave, and #VoteRemain.
Of course, tweets do not necessarily reflect the voting intentions of the Tweeter, but the firm notes the significant difference between the two is definitely of interest while it's already been noted that Brexiteers are the more vocal in the EU debate.
"The fact that Leave-related hashtags are registering at nearly double the rate Remain ones are is definitely interesting," the firm said.
And the social media sentiment has piqued the interest of firms wanting a heads up on the outcome beyond the polls.
The world's biggest asset manager, BlackRock, has at least 20 people tracking the debate on Twitter.
"There are a huge amount of people trying to work out the Brexit result, completely ignoring polls, looking at social media and trying to work that through... BlackRock's part of that process. We're still trying to work out what's going to happen, by the way, but we're looking at a lot of different things," said one of the firm's senior directors, Rob Fairbairn at an event this week Reuters reports.
While the influence of social media on voting intention is far from straightforward - just like press coverage - there is one startling indicator of its potential power and influence in the EU referendum.
On 3 June, Facebook put voter registration reminders on UK users timelines. That correlates with a huge jump in voter registration applications, particularly among young people.
The Brandwatch data also analysed the political figures being mentioned in relation to the EU referendum conversation. And for anyone who may have noted the hushed tones of the Labour leader in the debate, it will be no surprise to find Jeremy Corbyn is hardly at the top of the list - but even Presidential hopeful Donald Trump is more connected with the whole thing.