a person or company that invests money (= gives or lends it in order to make a profit) in new companies, especially when this involves risk

Many biotech companies are small start-ups, backed by venture capitalists. 许多生物技术公司是得到风险资本家支持的小型初创企业。

Venture capitalists seldom invest in an untested idea. 风险资本家很少投资于一个未经测试的想法。