Diffusion Index vs. Tick Index?

A diffusion index tracks how many stocks in an index are rising over time, usually on a daily basis. In other words, it counts how many stocks have risen since the previous session’s closing. The tick index is a shorter-term breadth indicator that counts how many stocks have increased in value vs decreased in value. An uptick is a traded price that is higher than the previous one, while a downtick is a traded price that is lower than the previous one.