In the early 1900s, purchasers of stocks, bonds, and other securities were described in media, academia, and commerce as speculators. Since the Wall Street crash of 1929, and particularly by the 1950s, the term investment had come to denote the more conservative end of the securities spectrum, while speculation was applied by financial brokers and their advertising agencies to higher risk securities much in vogue at that time. Since the last half of the 20th century, the terms speculation and speculator have specifically referred to higher risk ventures.