Data is one of your most valuable assets when you invest. Especially when you limit yourself to select the 5 best mutual funds for yourself, for example. If you are working with information that is not relevant or incorrect, making the right decision becomes more like a gamble.

Let's look at a bad example:

Google Finance

I have read and seen different examples of information that has been published there that is not correct. There are of course good examples with a lot of reliable data, but that is the tricky part, when 95% is reliable and correct you assume the rest is as well. Therefore is it important to stay alert and always question the information for example a mutual funds return on a fact sheet if it’s making sense or not.
Let’s look a good example of consistent reliable information for investors:

Morningstar

The fact sheet and information from Morningstar is highly accredited and reliable in the market. Once you see a fact sheet from Morningstar with a mutual fund from a technology company you can almost guarantee that the information on it is correct.

Another blogger that shows more information about this with evidence about google finance: http://www.theglobeandmail.com/globe-investor/meet-canadas-best-financial-bloggers/article624635/