Bid ask spread is the most fundamental area of microstructure theory, and it runs through microstructure researching.

买卖报价价差是微观结构理论中最基础的研究领域，并且贯穿于微观结构理论研究的始终。

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They improve the quality of the prices on the exchanges by lowering the bid-ask spread.

它们通过降低买卖价差改善了交易所的价格质量。

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The difference between bid and ask is the profit for the dealer and the bid-ask spread is the profit for the dealer.

中间商的利润来自出价和要价的差别，差价就是中间商的利润。

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The difference between bid and ask is the profit for the dealer and the bid-ask spread is the profit for the dealer.

中间商的利润来自出价和要价的差别,差价就是中间商的利润

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By comparison, the bid ask spread for the large much traded SPDR is a very reasonable 1 cent and even very large trades will not move the market.

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The best way to protect yourself is to use limit orders when placing an order to buy or sell a stock or an exchange-traded fund. (See How Your Buy and Sell Orders Get Filled for more.) Look at the bid-ask spread and set your price limit at the bid for selling a stock and at the ask for buying a stock.

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One issue for investors, according to Mr. Rosenbluth, is that this two-year-old fund is thinly traded and can have a wide bid-ask spread (the difference between the prices potential buyers "bid" to acquire shares and the prices potential sellers "ask" to part with theirs).

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