What variables are used for the Institutional Activity Index (IAI)?

I've been looking for various ways to get more information about institutional trade action. Although weekly COT report is available, it's already outdated by 1 week at the time the report come out every Friday. As a beginner in QF, I am interested in knowing what variables (and other factors) are available for trying to better understand the current (near real-time) market, from the institutional perspective.

Then I came across some proprietary thing called the Institutional Activity Index (IAI), from here. Where they present a graph like this:

Now, this is finally interesting, but I fail to see what kind of ingredients are needed to do such a thing, and if, perhaps, there are already indicators or other openly available tools for getting the data needed to re-create this? As I see it, if it is not reproducible, it's probably just a sales scam.

Question:

• (a) What data/information would be needed to get institutional buy/sell order data?

• (b) Where would I have to look to get such data?

PS. I am currently focusing on the currency markets.

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