How can I get intraday prices of a mutual fund? (Mine are Oppenheimer funds.)
This idea does not make sense for most mutual funds.
The net asset value, or NAV, is the current market value of a fund's holdings, minus the fund's liabilities, that is usually expressed as a per-share amount. For most funds, the NAV is determined daily, after the close of trading on some specified financial exchange, but some funds update their NAV multiple times during the trading day.
I am not certain, but I believe that OppenheimerFunds does not report intraday prices. I would call them up and ask.
Like others have said, mutual funds don't have an intraday NAV, but their ETF equivalents do. Use something like Yahoo Finance and search for the ETF.IV. For example VOO.IV. This will give you not the ETF price (which may be at a premium or discount), but the value of the underlying securities updated every 15 seconds.