This portion of buyback stocks could generate its incoming ( when stock prices go up), which in turn help offset
r = P/E , making this ratio go up slowly .. which again could attract further investing.
Only relative big companies have extra cash to do buying back, small companies will not have that power.
So S&P 500 is the index to go, not RUT ...
QQQ is different since people don't care about P/E for tech companies .
Therefore, QQQ is the best, next is S&P 500 ...