but i think satoshi is dead already, coz when btc price was rocket high, he could have moved those btc of his and live happy retirement life.,
Just because Satoshi missed the opportunity of selling his bitcoins during the peak doesn't mean he's dead. There's other possiblities too, it could be his decision to not move those coins and intentionally lost his wallet or wherever the keys are stored.
he didn't mind disappearing for years, i don't think he cares his millions of BTC for if he does he would have sold them. i think he deliberately burned those coins himself. what matters is that those coin will not circulate in the market and be dumped.
Even if Satoshi sells all of his bitcoin the crash would only last for some time because the market always recover over time.