In his latest Crypto Outlook, Bloomberg's Mike McGlone notes the Grayscale Bitcoin Trust (GBTC) is now trading at a modest discount to its underlying bitcoin (BTC-USD) holdings. As recently as a few weeks ago, the Trust was selling at a whopping premiumIf past is prologue, suggests McGlone, that might mean a bottom in bitcoin, which fell to about $43K last weekend from $58K a few days earlier (it's currently at $49.1K).Cycles are always changing though. Another possible reason for the evaporation of GBTC's premium: The launch of the Osprey Bitcoin Trust (OBTC), with fees far lower than the Grayscale product, not to mention a number of other vehicles with which investors - who otherwise might not be able to buy bitcoin directly - can invest in the crypto.McGlone also takes a look at bitcoin's famously high volatility. Comparing it to Amazon, McGlone reminds that Jeff Bezos' company was also wildly