investor; funder; financial contributor
A person or entity that provides funds, typically for a project, business, or cause. Neutral term; can be used in business, nonprofit, or personal contexts.
The project has multiple funders.
He is known as an anonymous financial contributor.
投資家 specifically means an investor who puts money into financial assets or businesses expecting a return, while 資金提供者 is broader and can include donors or sponsors without expectation of financial return.
出資者 is a legal or business term for a person who contributes capital to a company or venture, often implying equity. 資金提供者 is more general and can refer to any provider of funds.
Compound of 資金 (funds, capital) + 提供 (provision, supply) + 者 (person). The word follows a standard Sino-Japanese compounding pattern.