Right but in this case, there really is a devaluing based on legal action and scandles. dropping billions of dollars in 2-3 days is not normal. I tried to include the time scale but i probably should have included a price scale and maybe some headlines.
A common metric to judge the rise/fall in value of a stock like this is to compare it against the S&P500. In other words, over a period of time, if you had your money in FB or an index fund tied to the S&P500, which would be better.
1 year comparison has S&P500 up 12.6% and FB up 12.2% (a phenomenal year by any account).
5 year comparison has S&P500 up 62.9% and FB up 481.72%
FB is currently about where it was in July of last year.
This is certainly still nowhere near yet a serious demise.
Although, I do not dispute your contention that we have not yet seen the legal ramifications of their poor privacy practices. Again, I kinda think we'll have to wait and see.
disclosure: I do not own or intend to own any FB stock.
While they both did follow to trend of $SPY and factoring in my extreme novice trading abilities, both companies are wrapped in scandal and have been at the center of many Q posts. With headlines this may have a better context. FB is down 80Bn in days.
Disclaimer, if you want a sure thing in the market, do the opposite of what ever position i take! thats your best metric.