While no one knows when the current bull run will end, it is wise to exercise caution at this point. When the winds change, it will be sudden and few will have seen it coming. There are values out there, but they are very hard to find now - like a needle in a hay stack.
Today the market appeared to shift markedly away from the, heavily traded tech stocks and long-time market leaders to a more diverse basket. Oils were up (VLO, CVX) significantly and retailing rose as well from their down trodden pandemic positions (ROST, SKT).