You're oversimplifying the complexities of valuations. The market obviously felt that $150 was fair value not too long ago, but as explained the valuation landscape has since shifted due to the increase in the risk-free rate.
This is why investors should buy and hold a company with good fundamentals rather than try and time the market, unless it's selling for capital preservation and risk management. It's hard to perfectly time the ups and downs.
If I could tell you the FAIR value of a stock at any given time I'd be a billionaire.
APT Price at posting:
$105.88 Sentiment: Hold Disclosure: Held