There are a number of places in the new guidelines that increase the rigor required for timestamping data. One key part covers SI’s (systematic internalizers) who operate kind-of like private exchanges. TimeKeeper’s ability to produce traceable audit and to use multiple sources is designed for precisely this kind of application.
Moreover, the inclusion of the timestamp in the pre-trade information published by the SI is a key information for the client to better analyse ex-post the quality of prices quoted by SIs, and in particular to assess with accuracy the responsiveness of the SI and the validity periods of quotes. Without a timestamp assigned by the SI itself, market participants would need to rely on the information potentially provided by data vendors, the timestamps of which would be less accurate, especially when quotes are published through a website as pointed out by some respondents to the question on access to the quotes of SIs
Image is by Hans Holbein the Younger (1497/