How can I make use of sed (Stream Editor) to parse a html file for the required data I needed? Kindly explain to me.

I think what you are looking for is grep (get regular expression) it is used to pull specific lines from a file. you could then use awk to strip out the fields you want.

It really depends on the format of the actual file in question. The page you directed to shows the data to be on multipe lines and this can be a pain. try

grep ticker <filename>

where <filename> is replaced with the name of the file you downloaded. Also look into xml which is the format used and can actually be read straight into your database.