When a limit order for a security is entered, it is recorded by the Securities Commissioner. As buy and sell limit orders are added, the specialist records all related orders in the limit order book. When the market price reaches the preset limit price, the specialist will execute these orders at or below the limit price.

Key Points

• The limit order book is a record of unfilled limit orders maintained by the securities specialist of the exchange.
• A limit order is an order to buy or sell a security at a specific price or better.
• When a limit order for a security is entered, the Securities Commissioner records it.
• As limit orders for the purchase and sale of securities are issued, the Specialist records all such orders in the limit order book.

Understanding limit order books

Specialists who manage the limit order book are responsible for ensuring that priority orders are executed before other orders and completed before orders submitted by other traders (such as floor brokers and market makers) at the same or worse price.

Specialists profit from the spread between buy and sell orders on their limit order book. With the advancement of trading system technology, this process has transformed from manual operations to large-scale automated trading.

Track limit orders

In 2000, the Securities and Exchange Commission (SEC) began creating a centralized limit order book, a system that electronically tracks limit orders on exchanges. [1] This electronic order tracking system automatically matches the best order pairs in the system to implement transactions. The best order pair consists of the highest bid price and the lowest ask price.

The bid price is the price at which a securities commissioner or exchange is willing to sell a security, or the price at which an investor can buy the security. The ask price, or ask price, is the price at which a securities commissioner or exchange is willing to buy a security, or the price at which an investor can sell the security.

When a limit order is entered into a trading system and processed by the specialist responsible for that order book or electronic order database, it remains valid in the system until it can be matched to a suitable trade and then executed. Buy limit orders are placed within the upper price range. An investor will say, "I don't want to pay more than

Sell the stock at price X. "

Eligibility conditions for limit orders

Limit orders can contain "qualification conditions." If the order does not have qualifying conditions, the request is only valid during the market trading day, called a "daily order", and may expire without a fill or only a partial fill.

If the investor's order is "based on

Buy 10,000 shares at 32 or better, that's what qualifies for this order.

If an investor's strategy calls for an order of 10,000 shares to be filled at any time at the requested price or better, the request can be entered as "Buy 10,000 shares of XYZ GTC at $32." A "good until canceled" order instructs the market to keep buying those stocks until the order is canceled, even if each purchase is only 100 shares and lasts for several weeks. Investors want the order to be executed regardless of how long the market takes to fulfill it.

Another qualifying condition is AON, or "all or nothing." Investors may not want the order to be only partially filled, so use this condition to instruct the market to execute the order when all 10,000 share requests are met, otherwise no purchase will be made.

There are other types of order qualifications that allow investors to ensure that trades are executed in accordance with their specific investment objectives, and in each case define the "limit price" that the investor imposes on the market.

Special consideration

If the order is triggered after the market price reaches a preset level, the investor will get the requested price. However, limit orders are not guaranteed to be executed. In other words, the order can only be filled when the price reaches the limit price. Limit orders are helpful to investors because they ensure that investors will not pay more for a security than the preset price initially set.

References

[1] U.S. Securities and Exchange Commission. "The Nasdaq Stock Market Form IExhibit E," Page 7. Accessed May 23, 2021.

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限价单的资格条件

限价单可以包含“资格条件”。如果订单没有资格条件，则该请求仅在市场交易日内有效，称为“日单”，可能会在没有成交或仅部分成交的情况下过期。

如果投资者的订单是“以$32买入10,000股XYZ普通股”，则表示他们请求以$ 限价单簿是一种由负责交易所的证券专员维护的未成交限价单记录。限价单是一种买入或卖出证券的订单，要求以特定价格或更好的价格进行交易。买入限价单是指以预设价格或更低价格买入，而卖出限价单则是指以预设价格或更高价格卖出证券。

当证券的限价单被输入时，它会被证券专员记录在案。随着买卖限价单的增添，专员会在限价单簿中记录所有相关订单。当市场价格达到预设的限价时，专员会以或低于限价执行这些订单。

关键要点

• 限价单簿是由交易所的证券专员维护的未成交限价单记录。
• 限价单是一种以特定价格或更好价格买入或卖出证券的订单。
• 当证券的限价单被输入时，证券专员会对其进行记录。
• 随着证券买卖限价单的发布，专员会在限价单簿中记录所有这些订单。

理解限价单簿

管理限价单簿的专员负责确保优先订单在其他订单之前被执行，并在其他交易员（如场内经纪人和做市商）提交的相同或更差价格的订单之前完成。

专员从其限价单簿上买入和卖出订单之间的价差中获利。随着交易系统技术的进步，这一过程已经从人工操作转变为大规模自动化的交易。

跟踪限价单

2000年，证券交易委员会（SEC）开始创建一个集中限价单簿，该系统以电子形式跟踪交易所上的限价单。[1] 这个电子订单跟踪系统能够自动匹配系统中最佳的订单对以实现交易。最佳的订单对由最高的买入价和最低的卖出价构成。

买入价是证券专员或交易所愿意出售证券的价格，或者是投资者能以此价格买入证券的价格。卖出价或叫要价，是证券专员或交易所愿意买入证券的价格，或者是投资者能够以此价格卖出证券的价格。

当限价单被输入交易系统并由负责该订单簿的专员或电子订单数据库处理时，它会在系统中保持有效，直到其能被匹配到合适的交易然后执行。买入限价单是在上限价格范围内下达的。投资者会说：“我不想为这只股票支付超过