I always assumed angel investing (at least as it emerged originally) was essentially philanthropy with the motivation being it gave very rich people a way to nudge things they liked into existence and provided them with a semi-cheap way to keep their network fresh with young, hungry, interesting new people. Bonus it might very occasionally turn in to a lottery ticket (but that wasn't the primary driver of making the investment).
This seems to be a big part of it, but is there a separate word for it? It’s definitely not philanthropy because it’s not directed at public good.
Economics must have made a term for this part of the venture ecosystem. “Seed capital” misses the significant social and class aspects of the behavior.
Historically, the term you're looking for might have been "patronage". Wealthy individuals supported artists, scientists, or explorers not purely for financial return, but because they believed in the person, the cause, valued the association, enjoyed the influence, or whatever else.
