The function of OSBP2 (oxysterol binding protein 2, Ensembl gene identifier ENSG00000184792) is as follows. Mediates the bidirectional lipid exchange between intracellular compartments and the plasma membrane, delivering cholesterol to the plasma membrane while transferring PI(4,5)P(2) to internal organelles, thereby modulating membrane lipid composition and associated signaling pathways (PubMed:30581148, PubMed:32914503). Binds 7-ketocholesterol (PubMed:11278871). Acts during spermatid development where its function is required prior to the removal of cytoplasm from the sperm head (By similarity). {ECO:0000250|UniProtKB:Q8CF21, ECO:0000269|PubMed:11278871, ECO:0000269|PubMed:30581148, ECO:0000269|PubMed:32914503}.