stock(s) vs stockpile

stock(s)

stockpile

noun
  • A supply of nuclear weapons kept by a country; a nuclear stockpile. 

  • A pile of coal or ore heaped up on the ground after it has been mined. 

  • A supply (especially a large one) of something kept for future use, specifically in case the cost of the item increases or if there a shortage. 

verb
  • To accumulate or build up a supply of (something). 

  • To build up a stock of (nuclear weapons). 

  • To heap up piles of (coal or ore) on the ground after it has been mined. 

  • To build up a supply; to accumulate. 

How often have the words stock(s) and stockpile occurred in a corpus of books? (source: Google Ngram Viewer )