Updating Process

When the desired portfolios have been constructed, we update all the models selected. We obtain 15 years of data from the most accurate financial databases available.

This process involves an extended data cleansing procedure. During this process we identify incomplete, incorrect, inaccurate or irrelevant parts of the dataset and then replace, modify or remove this dirty data.

One of the most common definitions for closing prices is "the price of the last transaction for a security in a trading session" or words to this effect. Others simply use the phrase "the final price for a security on a given trading day".

Unfortunately none of these definitions are accurate. The closing price can be a myriad of things, ranging from simply the last transaction for a security for the day to a price derived from a complicated calculation or process. The closing price can also vary within a market where one rule applies to one trading segment and another rule applies to another segment.

It is evident that over the years closing price data has been an area where ambiguity and inconsistency are rampant. Research Unlimited's everlasting effort to develop the best quality platform for quantitative investment models includes understanding of the definitions, comparing the data and explaining any pricing anomalies.

During the process of collecting historic data, we continuously monitor completeness, validity, consistency, density & uniqueness of all data involved.