There is wide disparity in estimating what part of a gram, more or less, is needed per square meter in making QD film. There are many variables including the type of nanomaterials used, the ligands if any, what color they are - red or green, the thickness of the film, added shelling material, and the quantum efficiency or brightness of the QD. There may be more. So the numbers will be different for each separate quantum dot manufacturer. There is not one answer that can be based on fact. Each company keeps this information tightly held.

So the following hypothetical estimates is only to show what the total quantum dot market would be worth, and we will assume for example purposes only, that 1gram QD/square meter of QD film is necessary for that purpose. (This is a year or so old, so does not reflect new QMA developments which could increase these numbers in China)

The table in the link shows a leading market research company's estimate for QD LCD Display Market Forecast by Sq.Meter to 2020

As we can see 400 million square meters of QD are forecast for displays (only) by 2019.
That number requires the equivalent number in grams (@ 1gm/sq. meter).
@ $100/gram = $40,000,000,000 ($40 Billion)
@ $200/gram = $80,000,000,000
@ $300/gram = $120,000,000,000
@ $400/gram = $160,000,000,000

Are my numbers right?
What do you think our market share will be in 2019?