Hi,
Regarding the Yahoo Finance, there are libraries that can save your time if you use Python a.g.:
https://pypi.python.org/pypi/yahoo-finance
For ASX symbols, I used ASX.symbol (a.g. ASX.RRL) instead of the Americal symbol, a.g. AAPL and everything else is the same. Yahoo Finance is 15min delayed at its best.
There are also some local real-time data providers that use their own APIs. They charge an affordable price for personal use purposes.
Markets are always ahead of you. The moment you catch an existing situation, it is already part of history.
Cheers
