214 The Stock Market Crash—And After 
1919 total. These figures also show, however, that 
bonds are still the chief investment. 
Common Stock Investment May Be Overdone 
In an article published on May 28, 1928, I said 
that while the theory is sound, investment in com- 
mon stocks can be overdone, especially when every 
one is buying them. The codperative buying of 
diversified stock securities should be done with full 
knowledge that it may be affected by overspeculation, 
and that, after all, common stock investments are not 
based on guaranteed income. When the average 
yield of common stock falls below § per cent, the 
investor must look very sharply at the prospects of 
the companies in question, and then it is wise for him 
to buy other securities as well. 
The purchase of bonds and preferred stocks is 
more advisable if the commodity price level tips 
downward, as it has done since 1925. For when the 
price level of commodities declines, holders of bonds 
profit by the rise in purchasing power of the dollar, 
both in their interest and in their principal. 
Mr. Leland Rex Robinson, whose book on invest- 
ment trusts is standard, recently called attention to 
the generally high-grade character of securities pur- 
chased by leading investment trusts during 1929, 
and the great distribution of risks which many of 
them show in their holdings. Mr. Robinson dis- 
tinguishes, of course, between investment trusts 
proper and holding companies which control, man- 
age and finance groups of subsidiaries. These hold-