In the flat below, add a single letter to the first answer to get the second answer, without any re-arrangement in the order of the letters.

If more and more  _ _ _ _ _ _ _ _ _ the stock,
Its value may well _ _ _ _ _ _ _ _ _ _ .

Answer:

DEPRECATE
DEPRECIATE 

Credit:
The Enigma
NPL Magazine
July, 2019
R/EDS