S&amp;P 500 12 mth forward p/e at nearly 25x.

Should investors be worried?

$GSPC
$AAL $DAL $UAL $LUV $JETS $BA
$UNP $CSX
$LYFT $UBER
$FB $AAPL $AMZN $NFLX $GOOG
$WMT $HD $COST $DIS https://t.co/v81rfdjFzw