Lead investor is a company’s principal provider of capital, typically the entiy which helps originate and structure syndicated deals. The lead investor is the most actively involved member of the project and usually takes control of the financing arrangments. They typcially contribute the largest investment to the deal as well. If the deal, as a whole, is very large, a single investor will not want to carry all of the risk. The risk will then be divided amongst a "syndicate" and the lead investor will take the most responsibility and try to find other potential syndicate members.