You're quite welcome. We do what we can ;)
I've noticed that almost all of the most promising-looking start-ups are 'private' companies with no open market stock available. With this in mind, it might be wise to seek investment opportunities via private placements of one sort or another, depending on commercial viability & a whole lot of NDA-DD.
I spent a lot of time researching graphene & for ways to invest in this wonder-material as well. But I eventually came to the conclusion that, despite all the enthusiasm & the 8yrs since it won the Noble Prize award, graphene has yet prove itself in terms of commercial value. Notably, the inventors of graphene left it open-source, instead of claiming a patent on it. It seems to me that with this in mind, it would be hard for any one manufacturer to corner this market, & speaking of 'markets', there really is none other than for research projects, as far as I can tell. There will no-doubt be many uses for graphene in the future, but the way if fraught with techno obstacles (see multiple publications) & since graphene has no band-gap, it will most likely need to be used in conjunction with other hybrids of one sort or another. Still, that's not to say that a wise investor shouldn't keep looking ;)
Happy Trails & GL2U
