NVDA forward PE is 42.48, which isn't super crazy relative to other big tech companies (MSFT over 30). I suspect ARM's forward PE is double that ratio (>80).
If NVDA's forward projections are correct, and they can maintain that same growth, then there is still room for upside. Personally, I'm not playing this game of musical chairs because I don't think these valuations are sustainable, but as they say, the market can stay irrational longer than you can stay solvent, so shorting is a terrible idea.
Others do seem to be backing off, but there is still definitely a lot of way overvalued tech out there.