You can use Yahoo's look up service using Jonathan Christian's .NET api that is available on NuGet under "Yahoo Stock Quotes".
https://github.com/jchristian/yahoo_stock_quotes
//Create the quote service
var quote_service = new QuoteService();
//Get a quote
var quotes = quote_service.Quote("MSFT", "GOOG").Return(QuoteReturnParameter.Symbol,
QuoteReturnParameter.Name,
QuoteReturnParameter.LatestTradePrice,
QuoteReturnParameter.LatestTradeTime);
//Get info from the quotes
foreach (var quote in quotes)
{
Console.WriteLine("{0} - {1} - {2} - {3}", quote.Symbol, quote.Name, quote.LatestTradePrice, quote.LatestTradeTime);
}
EDIT: After posting this I tried this exact code and it was not working for me so instead I used the Yahoo Finance Managed Api however it's not available via NuGet. A good example of use here
QuotesDownload dl = new QuotesDownload();
DownloadClient<QuotesResult> baseDl = dl;
QuotesDownloadSettings settings = dl.Settings;
settings.IDs = new string[] { "MSFT", "GOOG", "YHOO" };
settings.Properties = new QuoteProperty[] { QuoteProperty.Symbol,
QuoteProperty.Name,
QuoteProperty.LastTradePriceOnly
};
SettingsBase baseSettings = baseDl.Settings;
Response<QuotesResult> resp = baseDl.Download();
Also if you just want to download the stuff stocktwits api has a download link for the symbology and industries under "Resources" http://stocktwits.com/developers/docs