After those statements I doubt you have much first hand experience in the market and you just google stuff!
Brokerage companies and Banks that have trading sections of their business and particularly those Banks that finance these public listed companies have huge holdings in these companies. Often they engage in share lending and borrowing from and for their clients. This involves at times heavy shorting in these companies.
As for HFT, they trade in fractions of a cent ie they supress the prices and lets say they buy at 51.2c and sell it at 51.4c and they do this all day every day on a lot of small . It is important to understand that normal retail investors don't have the option of buying in fractions of cents. The SP is most often restricted by sharewashing which is supposed to be illegal but as the ASX has its own Dark Pool they are not going to stop it and then there is ASIC which is pretty much impotent and is now having its funding cut by this current Australian government.
U.S. market is being pumped up by the U.S. Fed through its banking arms like G.S. JPM BOA etc. The U.S. Fed has said all along it engages in buying securities, Bonds, mortgage backed securities from those Mortgage brokers that went bust during the beginning of the GFC. This is what the QE is about keeping these banks and companies afloat but without giving any money to the people, it is just used to pump up the markets and protect the U.S. Dollar.
