The term overvalued is a misnomer for describing a stock's worth.
i have noticed that people who use the term 'overvalued' are usually poor.
even Buffett put 40% of his wealth into GEICO when everyone around him, including Graham, thought it was 'overvalued'. That stock investment made him who he is now. Everyone seems to think he is some sort of super diversified wizard but he was far from it when he was building his grubstake back in the 50s 60s and 70s. He really put some big positions on in the stocks that he had conviction in.
I look Tesla now which is what 90% of the investing population would call 'overvalued'. Who cares if it's 'overvalued'. So long as it's going up, hold onto it or buy more of it. Overvalued at $200, overvalued at $300, overvalued at $400.........Do you want me to keep going?