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.