In a crowded field of social media influencers who dispense financial advice, Sheikh Joe Bradford has found his niche. An expert in Islamic law, Bradford teaches his audience how to invest their money the halal way.

The comment sections of his accounts—where 85,000 followers across Facebook, Instagram and Twitter convene—are full of questions about exactly which investments are allowed for Muslims and which are forbidden, or haram. The queries reveal the challenges facing a generation of financially and technologically literate Muslims who want to know how traditional Islamic guidelines apply to everything from stocks to nonfungible tokens.