“A pie doesn’t grow through its slicing”

The popular book A Random Walk Down Wall Street (1999) stated: “These studies lend support to the old Wall Street maxim, ‘A pie doesn’t grow through its slicing.’” A pie (wealth) is actually diminished by slicing and dividing it. The origin of the saying is not known.
 
A similar saying (cited since the 1930s) is: “You cannot multiply wealth by dividing it.”
       
 
Google Books
A Random Walk Down Wall Street,
including a life-cycle guide to personal investing
By Burton G. Malkiel
New York, NY: Norton
1999
Pg. 187:
These studies lend support to the old Wall Street maxim, “A pie doesn’t grow through its slicing.”
 
Google Books
Investment Analysis and Portfolio Management
By Prasanna Chandra
Tata McGraw-Hill
2008
Pg. 23 (Proverbial Investment Wisdom):
A pie doesn’t grow through its slicing.