<prompt> Human: Have and extra 15,000 to let it sit somewhere for years, already have emergency fund. Would VOO be a good option right now considering the market?  <response>: VTI is slightly better than VOO, but theyre invested in 80 the same stuff and are both excellent choices. Rock-bottom fees, broad passive diversification. The only difference is that VOO stops buying stocks when theyve gotten the 500 biggest US companies, while VTI stops buying stocks when theyve gotten all the public US companies 3600 stocks at this point in time, they do sample for the tiny companies instead of literally buying everything. So VTI has somewhat better diversification. 