The law says its aim is to diminish, eliminate or prevent excessive speculation.

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Singapore's government imposed the tax in December 2011 on most foreigners to fight what it contends is excessive speculation in the property market.

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Two of the commissioners who voted in favor, Chairman Gary Gensler and Commissioner Bart Chilton, did so because they believed these position limits would prevent excessive speculation.

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Two schools: One is saying that the spike is the result of excessive speculation while the other holds the more traditional position that the increase is a function of supply and demand.

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In China, for instance, some foreign investors made aggressive bets on the country's luxury housing market in the past few years, only to get burned after the government moved to rein in excessive speculation.

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But Sebi chairman, DR Mehta, told the BBC that he was confident the markets would respond well to a measure which will not only curb excessive speculation, but do away with a system which was sometimes used by unscrupulous operators to rig the stock markets.

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That doesn't mean that all deals will turn out well, but the reliance on cash will temper excessive greed and speculation.

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Both that plan and one from the House are expected to include language to curb excessive oil-market speculation, which many lawmakers believe has artificially caused a spike in oil prices.

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"Speculation has been excessive, " says Chia Yew Boon of Crosby Securities.

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