So if you wondered what a shell company is, one way to get a publicly traded company is to buy the "shell" of an existing company that is already public but wound down operations.
Sort of a take over of just the name, incorporation documents and exchange documents that let it list. You'd then delist and have your shares only trade OTC. This helps explain why they haven't filed any financials for the past few years.
If you look at its trading history, NERO US Equity if you have a Bloomberg terminal, you can see that it traded a few hundred shares a day and slowly climbed up each day. This probably indicates that the shares are very tightly held. So the owners can't really cash out by selling their shares, but they can possibly use the shares as collateral.
Being so tightly held also eliminates the possibility of shorting the company, though shorting any OTC symbol is always a bit sketchy.