Not really. The decision to not sell and to not buy is itself reflective of the price. If a stock is super cheap, people will buy. If the stock is priced fairly or overpriced, few people will buy. Same goes for selling.
>> Length of ownership AND relatedly original cost basis. I think a lot of stocks can seem to defy gravity (i.e. high PE and/or high P/FCF) when the founder and the early investors HODL stocks. At $0.0001 per share, HODLing (in say TSLA, META, MSFT, BTC) is easy since there is/was no upfront capital paid in and holding has essentially no cost basis - so there's no need to act like rationally like a later stage investor.
>> Founders and early investors can easily own up to 30-50% of the company and really its only when the founder retires/starts diversifying and the founder and early investors start to unload - does price discovery occur on the entirety of the shares outstanding.[1][2][3]
[1] Mark Zuckerberg Sold Facebook Stock Nearly Every Weekday Last Year For Almost 11 Months https://www.forbes.com/sites/rachelsandler/2022/01/06/mark-z...
[2] https://techcrunch.com/2013/02/15/zuckerberg-now-owns-29-3-p...
[2] Amazon founder Jeff Bezos decreased his stake to 24% from 42% in the first nine years after IPO.