Re:Index Investing Makes Markets and Economies More Efficien...
by Retric on Wednesday September 20, 2017 @08:02AM
(#15292742)
Stock buyback's are one example, but companies can also issue/aka create new stock from thin air and sell it. Though clearly less extreme than I was describing, the forces are similar.
Keep in mind that this doesn't (at least not naïvely) happen when one of the two increases or decreases in value relative to the other.