GBTC is the first steps to the BIT (Bitcoin Investment Trust) ETF, currently with filling for NASDAQ. OTC markets have less liquidity and participants than a main Stock Exchange. There are administration fees. The high demand by the limited players on the OTC market pushes the prices to a premium. When it becomes an ETF this will get balanced by ETF creations and cancellations (redemptions) for and with the underlying asset, Bitcoin. If you are an investor that need to got through a regulated market, or a regulated asset manager this is one of the few options. Rule for the pricing is determined transparently in the prospectus and there is a voluntary agreement from investors to buy/sell at this prices.
Yes and when these others become available, I would imagine the premium will be sucked right out of it. That is kind of my point in all of this. At this stage I would say the premium is much more likely to decrease from these levels going forward than it is to increase...