It is important as a primer not to conflate ANTIFA with Black Lives Matter, although there is certainly video evidence that ANTIFA has allied with BLM in many situations. By the way, for your pleasure, here is the author of The Anti-Fascist Handbook, Mr. Mark Bray.
ANTIFA does however receive grants from Soros and likely Tom Steyer.
BREAKING: @RefuseFascism Dark Money Exposed
“We did get a grant from [Soros]”