Re: Is everyone got the same data from CME or there are diffrent quality levels?
As an end-of-day data vendor I'll provide some perspective here.
Exchanges typically have multiple data systems from which quotes and trades are disseminated. Some are designed as real-time feeds, others are reference feeds, and others are summary feeds.
Then each data vendor may have their own way of interpreting these feeds.
For example, in the CME's official daily bulletins they often publish an Ask high rather than an actual trade high, because the CME's bulletin methodology is different from most expect. Another difference is some vendors may include spread trades in a summarised form, whereas others ignore spread trades. A further example in physical commodities is where exchange-for-physical trades may be similarly excluded.
Then there are the effects of cancelled/erroneous trades - do you remove them as if they never existed or would you have considered them intraday.
Many brokers do have direct feeds - others use data feeds from real-time vendors.
Ask your data vendor how they source their data and about these types of events.
Here's the CME's real-time data platform: http://www.cmegroup.com/market-data/...-platform.html |