This is the market's biggest driver : Companies are pulling out the big guns to hit earnings targets, pushing stocks ever higher.

MSN reports:

Quick, what is the stock market's biggest driver today?

Corporate earnings? Interest rates? The Federal Reserve? Some say the correct answer is something people rarely discuss: companies buying back their own stock.


Companies purchasing their own shares represent the single biggest category of stock buyers today, according to a study this month by Jeffrey Kleintop, chief market strategist at brokerage firm LPL Financial.


Only one other major group, individuals, is a net stock buyer now and individuals are buying less than corporations, Mr. Kleintop found.


Of six major groups he identified, hedge funds, foreigners, insiders and investment institutions such as pension funds and insurance companies all are net sellers, he found. He used data from the Fed, the U.S. Treasury, FactSet, the Investment Company Institute and other sources.

The Barack Obama stock market rally.