Warren Buffett: Investing VS Speculating

The line separating investment and speculation, which is never bright and clear, becomes blurred still further when most market participants have recently enjoyed triumphs. Nothing sedates rationality like large doses of effortless money.

But a pin lies in wait for every bubble.

And when the two eventually meet, a new wave of investors learns some very old lessons: First, many in Wall Street – a community in which quality control is not prized – will sell investors anything they will buy. Second, speculation is most dangerous when it looks easiest.