I'm no t sure the classic PE ratio is as useful for the S&P500, unless it's been the last few years. PE ratios haven't really explained tech, and their growth compounding is insane. Tech makes up like 8 of the top 12 stocks (2 are Alphabet).
AMZN is getting beat down a bit, and is looking more attractive.
The airlines are getting hammered and they had good news. I think people are freaking out and just pulling their money. It will make a good time to buy a few premium companies.