exchange of contracts vs transaction

exchange of contracts

noun
  • The act of exchanging contracts. 

  • The point or stage at which a conveyancing contract comes into existence between negotiating parties for the carrying out of a disposition of an estate in land; usually requiring the payment of a deposit. 

transaction

noun
  • A deal or business agreement. 

  • A social interaction. 

  • A record of the proceedings of a learned society. 

  • An exchange or trade, as of ideas, money, goods, etc. 

  • The act of conducting or carrying out (business, negotiations, plans). 

  • The transfer of funds into, out of, or from an account. 

  • An atomic operation; a message, data modification, or other procedure that is guaranteed to perform completely or not at all (e.g. a database transaction). 

How often have the words exchange of contracts and transaction occurred in a corpus of books? (source: Google Ngram Viewer )