GBTC seems to be one of the most popular ways for a "normal" person to invest in Bitcoin. However, a brief review of their SEC filings will show that the price of GBTC is significantly higher than the value of the Bitcoin per share. Additionally, because of the 2% annual fees associated with GBTC (per their filings), the amount of Bitcoin per share of GBTC will decrease each year.
Per the SEC filings (link below), each share of GBTC is "backed" by .094 Bitcoin. The numbers below reflect the average value of each of these assets as of Friday January 5, 2018:
.094 Bitcoin = $1,598
1 share of GBTC = $2,337
Premium paid per share of GBTC = $739 per share (46% premium).
Furthermore, the numbers below are based on the SEC filings as of the date they were submitted. So it is possible that the amount of Bitcoin per share of GBTC has decreased even further as a result of the 2% fees.
Keep in mind that the information above is only related to Bitcoin. Unlike owning Bitcoin directly, when a hardfork occurs, you are at the mercy of GBTC to figure out what to do with the coins produced from the hardfork (think Bitcoin Cash or Bitcoin Gold). For example, if you owned GBTC during the Bitcoin Cash hardfork, but sold soon after, you never received any benefit from the resulting split. Why? Because GBTC gave a dividend payment for holders of GBTC as of November 6, 2017, well after the Bitcoin Cash split.
The bottom line for me on GBTC is that current prices are SIGNIFICANTLY higher than the underlying value of their Bitcoin holdings (even if you ignore the 2% fee or the unknown about how they will handle coins created during a Bitcoin hardfork.
I hope you found this article helpful. Please let me know your thoughts!
https://www.sec.gov/Archives/edgar/data/1588489/000119312517013693/d157414ds1.htm