There are four indicators that make up the core market internals:
1 Breadth Ratio:
The ‘Market Breadth
’ or ‘Breadth Ratio’ is a volume ratio composed of volume flowing into up stocks versus volume flowing into down stocks.
The breadth ratio is expressed: Up Volume / Down Volume.
2 Advance/Decline Line:
The ‘Advance/Decline Line’ or ‘A/D Line
’ for short, is the second most important of the internals. This indicator tells us the net sum of advancing stocks minus declining stocks.
The A/D Line is expressed: # of Advancing Stocks – # of Declining Stocks
TRIN stands for TRaders’ INdex and was developed by Richard Arms in 1989 (it’s also referred to as the Arms Index
). Its main purpose is for detecting overbought and oversold levels in the markets
The Trin is expressed: # of advancing stocks / # of declining stocks divided by
volume of advancing stocks / volume of declining stocks
Tick Index gives us the relationship of stocks up ticking versus down ticking at their last traded price.
Each indicator has a separate reading for the NYSE and NASDAQ
See also: http://www.traderslog.com/market-internals