One of the tools that day traders use to make their trades is the market data
for their markets. The market data includes information about the prices, and the completed trades for the market, and is available in two different levels depending upon the information that is required :
交易员用来交易的一个工具是市场的market Data。这个market Data包括价格信息，市场完整的交易信息，根据信息不同可以有不同层级需要：
Level 1
Basic market data is known as level 1 market data, and includes the following information:
基础市场数据被称为 level 1 market data，包含下列信息：
- Bid price: The highest price that a trader is willing to pay to buy a contract
- 出价：交易员买一个合同想支付的最高价格；
- Bid size: The number of contracts that are available at the bid price
- 投标大小：在此出价下需要的数量，感觉这个应该是quantity吧；
- Ask price: The lowest price that a trader is willing to accept to sell a contract
- Ask size: The number of contracts that are available at the ask price
- Last price: The price at which the most recent trade was completed
- 最近成交价
- Last size: The number of contracts that were traded in the most recent trade
- 最近成交数量
Level 1 market data provides all of the information that is needed to trade using most trading systems, including the moving
average bounce, zero line cross, and pivot
point bounce trading systems.
Level 1 market data提供了大多数系统所需的交易信息。
Level 2
Additional market data is known as level 2 market data, the order book, or the depth of market, and includes the following additional information:
另外的市场数据被称为 level 2 market data，orederbook，市场深度，会包含下列信息：
- Highest bid prices: The highest 5 or 10 prices (depending upon the market) that traders are willing to pay to buy a contract
- 最高出价表：一般是最高的5或10个最高出价，其实这里是个表，排序后的出价表。
- Bid sizes: The number of contracts that are available at each of the highest bid prices
- 出价每层价格的数量；
- Lowest ask prices: The lowest 5 or 10 prices (depending upon the market) that traders are willing to accept to sell a contract
- Ask sizes: The number of contracts that are available at each of the lowest ask prices
Level 2 market data provides the additional information that is needed to trade using trading systems that follow the order flow, and advanced volume based trading systems. Level 2 market data is also known as the order book, because it shows the orders that
are currently pending for the market, and is also known as the depth of market, because it shows the number of contracts that are available at each of the available prices.
Level 2 market data提供了交易所需的额外信息，被称为orderbook。它显示了市场上最新的orders，被称为市场深度，因为它显示了每个可交易价格上的将交易数量。
Availability and Pricing
All market data originally comes from the exchange that offers the market, and day traders receive the market data via their day
trading brokerages. Both level 1 market data and level 2 market data are available for most day trading markets, including most futures markets
and stock markets. The fees for level 2 market data are usually slightly higher than level 1 market data.
所以的市场数据来自交易所提供给市场，交易员收到市场数据通过day trading brokerages。level1和level2在大多数交易市场都是可得的，包括大部分期货市场和股票市场。