I would probably put a little more error checking into the extracting the numbers from the web page (make sure they're the proper size, etc), because that would really suck if they changed the HTML on that page and:

What!?!? Those were the numbers for yesterday!?!? My perl script said I lost and I tore up the ticket. Arg!!!

Which kind of makes you think, to what extent would you trust a computer to do something for you? Would you let a program analyze the market and trade your stocks for you?