split up vs stock split

split up

verb
  • separate, disassociate, cause to come apart. 

  • Cease to be together, break apart from the group. 

adj
  • Divided or separated. 

stock split

noun
  • An event wherein a company that has previously issued shares of stock increases the number of shares while reducing the value of each share accordingly. 

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