To add to the 1st bullet, in this 2013 Q&A with Holden he talked about how GiveWell focused on “proven” interventions like bednets over “speculative” ones like biomedical research because they were easier to evaluate (“easier” being relative, even bednets were pretty hard); even back then he was saying the speculative interventions were better and that the partnership with Cari Tuna and Dustin Moskovitz that created GiveWell Labs (which turned into OP/CG) enabled this pivot.
To add to the 1st bullet, in this 2013 Q&A with Holden he talked about how GiveWell focused on “proven” interventions like bednets over “speculative” ones like biomedical research because they were easier to evaluate (“easier” being relative, even bednets were pretty hard); even back then he was saying the speculative interventions were better and that the partnership with Cari Tuna and Dustin Moskovitz that created GiveWell Labs (which turned into OP/CG) enabled this pivot.