QUOTE(sabrateur @ Jun 20 2008, 12:08 PM)
Actually, if only long term buyers are in the market, this is what will cause bubbles. Everyone buy and keep, nobody sells.
It is the first time, I heard long term buyers are the one causing bubbles.
Historically proven, it is those speculators are the culprit for those bubbles making range from 2000 tech bubble, US subprime, China stock market bubble recently. Those bubbles are being created by greed of people/investor/speculators. Those speculators keep on buying because they anticipated price will go even higher so with buying continous pile up so does share price, commodities price etc. They don't care about fundamental or valuation as long as there are takers/buyers at higher price then they can make profit out of it. And with easy profit and this cycle role on, bubble become bigger and bigger until the bubble is too big and can't sustain then bursting, then all bloods across the street, just like subprime recently causing massive billions and billions of loss on banks and investment banks.
Long term investors don't mean they won't sell, but mean they intend to keep it for long term in the first place when initial buy. They are not the one going in and out of the market frequently which reduce the volatility of the market. In fact, they are the one cuhsioning the down trend effect and stablise the market.
Long term investors don't mean they are buying blindly also which create buying force that create any bubbles. They generally look for value as it is meant to keep for long term.
Another point is long term investors doesn't mean they fall in love with the stock forever, when profit is enough or see price way beyond the fundamental price then will sell to realise those profit.
Typically case would be Warren Buffett that everyone knew he is a long term investors, but he still sold petrochina shares he owns previously because he saw it is too expensive to hold on already.