Running FxCop on your assemblys is a good practice to keep your code clean and efficient. FxCop not only finds code that break “best practice” rules it also suggest´s how to correct them.

Some tips:

Properties should not return arrays

"Properties that return arrays are prone to code inefficiencies.
Consider using a collection or making this a method.
See the design guidelines for more information."

Specify format provider

"If an overload exists that takes an IFormatProvider
argument, it should always be called in favor of an
overload that does not. Some methods in the runtime
convert a value to or from a string representation
and take a string parameter that contains one or more
characters, called format specifiers, which indicate
how the value is to be converted. If the meaning of
the format specifier varies by culture, a formatting
object supplies the actual characters used in the string
representation. In scenarios where sorting and comparison
behavior should never change between cultures, specify
CultureInfo.InvariantCulture, otherwise, specify CultureInfo.CurrentCulture."

Example:
LastRefresh = Convert.ToInt64(marketFields[10], CultureInfo.InvariantCulture)

Download FxCop : http://www.microsoft.com/downloads/details.aspx?familyid=3389F7E4-0E55-4A4D-BC74-4AEABB17997B&displaylang=en