"Money Inflows" is mostly a huge myth. When investor A sells $10k bonds to investor B for $10k (who took cash out of a bank account for the purchase)  and puts the resulting $10k cash into stocks by buying stocks from Investor C for $10k who ends up with the $10k cash, not a dime has left the bond market and not a dime has entered the stock market and the same $10k is sitting in a bank account. Investors as a population are powerless to inject new money into stocks or take money out of bonds by trading with each other. 

Similarly "cash on the sidelines" is nonsense since when it is used to buy stocks it will go to the sellers bank account and remain on the sideline.

These silly terms are thrown around in the newspapers and financial press all day long when it is clear that they make no sense at all.