Stocks took their worst beating of the year yesterday on Wall Street as analysts began to question whether the long-running bull market was coming to an end.

The Dow Jones Industrial Average plummeted 299.43 points, or 3.40 per cent, to close at 8,487.30. The main barometer on Wall Street has now fallen 9.1 per cent since hitting a record high July 17th.

Analysts start to speak of a market "correction" when indices lose 10 per cent in a given period.

The Dow is now perilously close to such losses and some of the most optimistic market watchers - known as bulls - are beginning to have doubts.

For example, Ralph Acampora of Prudential Securities, dubbed "Mr 10,000" for his predictions that the Dow would hit 10,000 points by the end of the year, yesterday tempered some of his optimism.

He warned that the Dow could fall by 15 to 20 per cent in the coming months from its mid-July record high.

"I think we're at the beginning of something that's bigger than I thought," he told CNBC television.