Crunchbase is a (relatively) cheap product for this kind of research.
I'd suggest talking to other vc-funded fintech founders who've raised at your stage in the last couple of years, especially for products that sit in parallel spaces to yours. They'll know who the relevant fintech investors are because they'll have spoken to many of them.
I'd suggest talking to other vc-funded fintech founders who've raised at your stage in the last couple of years, especially for products that sit in parallel spaces to yours. They'll know who the relevant fintech investors are because they'll have spoken to many of them.