API

Yahoo! Finance – Yahoo Stock Quote API (CSV)

http://finance.yahoo.com/d/quotes.csv?s= a BUNCH of STOCK SYMBOLS separated by “+” &f=a bunch of special tags
**s=SYMBOL**: where SYMBOL is the actual stock symbol (e.g. 0001.HK)
**f=REQUESTED_FORMAT_STRING** where the REQUESTED_FORMAT_STRING is a string of letters representing what fields to be requested.
for example: http://finance.yahoo.com/d/quotes.csv?s=XOM+BBDb.TO+JNJ+MSFT&f=snd1l1yr
where some special tags are (thanks to Mike):

a
Ask
a2
Average Daily [...]