It still makes zero sense, it's pure emotion. Unless the speculation is for something far worse: a rapid plunge to negative growth (that doesn't appear likely right now).

Microsoft is growing at about 1/3 the rate of Facebook, and with the FB shares down 22% after hours (~$500b market cap), Microsoft has a real PE ratio at least 1/3 higher. The same crazy contrast exists for Google, Amazon, Netflix.

This is an emotional mis-pricing by the market, just as the drop to $150x in March was. I haven't bought after hours, but if the emotionalism continues tomorrow, it's an easy buy on further weakness.