Another, far more significant source of long-term borrowing by business were the issues of corporate bonds and notes which were often purchased not just by commercial banks but also by other financial intermediaries like mutual savings banks, savings and loan associations and especially life insurance companies which, according to Go had ended up holding almost as much of the corporate bonds as commercial banks by 1929 (12% vs 12,1%).
Overall, the total amount of corporate bonds and notes outstanding rose from $24,2 bln. in 1922 to $39 bln. in 1929. According to the chart below, the peak of bond issuing at the NYSE stock market was achieved in 1927 which represented a dramatic spike from the 1926 level.