Sudden Price Jump
Steep Price Rise
noun, する verb
Tall inflation of prices means that there was a sudden price jump and it's waaaay more expensive than it used to be.
こうとう
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
どうして株価がこんなに高騰しているんだ。
Why do stock prices suddenly jump like this?