Did you expect to find Soros literally handing out money from his own pocket to the Antifa? It's the same as expecting a drug-lord directly associating with his "soldiers". Not happening.
Tides foundation is known to behave as a "front" for big leftist philantrophers. Soros has been a consistent, heavy donor to the foundation, both directly and indirectly through his "Open Society" foundation.
http://www.groupsnoop.org/Tides+Foundation
Here is only one of the documents (from their own site) which show AFGJ receiving money from the Tides foundation.
http://www.afgj.org/wp-content/uploads/2016/08/AFGJ-990-2015-Small.pd
I'm not saying that Soros is necessarily even 100% knowledgeable where all of his donations go to, though I'm sure that he keeps up to date with the activities of some of the groups that his money is flowing to. The point is that through his donations, he is directly or indirectly a large reason as to why such movements continue to be energized. In the same manner how Arab countries funding radical Islamist sects are a reason why jihadist movements (their pro-violence wing) continue to function. Is there a direct link to be found between Gulf leaders and ISIS? Perhaps not. But we all know that there is a lot of smoke, and that if there wasn't a money flow into Islamic fundamentalism, these jihadist groups would likely die off.
Soros's overall, well-established history of funding what he calls "subversive activity" is clear. There are mountains of evidence from Eastern European countries, where he cares less about keeping a lid on his activities, as his activities there are generally seen in a positive light by Westerners. The relations between Soros and the Eastern European governments are nearly all hostile.
Here is an audio clip of him boasting about it (keep in mind that his idea of "repressive" regime is any right-wing government):
The statements that he has frequently made, out him as a megalomaniacal character:
http://articles.latimes.com/2004/oct/04/opinion/oe-ehrenfeld4
If I can gain entry to the site keeping track of the money flow within non-governmental organizations (needs registration), perhaps I can present more evidence to my case. Though I doubt that as a random civilian, I can somehow tie Antifa and Soros directly together. If I could, I would have a Pulitzer Prize sitting on my lap.
What I'm saying is that there is plenty evidence in favour of Soros being a donor to radical leftist causes. I'm not going to own up to American show-man Alex Jones's comments, as the direct interaction between Soros and these protests is impossible to prove, but he is certainly energizing such movements through his philantrophic actions.