Anyway, the subject is misleading. You should correct it lest it be misunderstood as a mega-bullish stand of BlackRock. This actually isn't BlackRock's opinion or view. This is simply the personal view of the three authors who happened to be working with BlackRock. But this study is not in any way sanctioned by BlackRock itself.
I'm not sure I'd even call it the personal view of the authors. If you read the paper, the number quoted by OP (and various crypto-news outlets) is not even the conclusion. It's just the cherry picked result of one of two mathematical asset allocation models being applied to Bitcoin. The other model they apply, Cumulative Prospect Theory, comes to a slightly different conclusion:
In order to obtain finite solutions, we change the mean of BTC in the normal regime to correspond to a loss of 90%. That is, we set exp(𝜇2) = 0.1, or 𝜇2 = −2.303. We also change the probability of the bliss regime to 𝑝 = 0.001, with the same mean, 𝜇1, and standard deviation, 𝜎1, of the BTC bliss regime as the empirical estimate reported in Exhibit 3. This distribution has the same extreme right-hand tail payoff as the original process, but it occurs with a much smaller probability, 𝑝 = 0.001, versus the empirical estimate of 𝑝 = 0.036. Even with this tiny probability, the optimal BTC holding is 9.5% holding the 28-72 equity-bond portfolio fixed in pro-rata allocations. Exhibit 7, Panel B plots the CPT utility function for the three-asset BTC-equities-bonds portfolio. The maximum utlity corresponds to the optimal BTC holding of 9.5%, with the equity and bond holdings being held in the same 28-72 pro-rata allocation for the remaining 90.5% of the portfolio.
TL;DR: The authors apply two models, one resulting in a BTC allocation of 84.9% and a risk averse one, resulting in a BTC allocation of 9.5%. The latter one is not newsworthy nowadays, so of course everyone is only focusing on the bigger number.
(even 9.5% percent would still be huge, mind you)
I tried reading the entire paper but because of my very limited comprehension capacity of the technicalities the authors were talking about, I decided not to continue.
I assume those who cherry-picked didn't also thoroughly understand the paper. They spread the cherry-picked lines, nonetheless. OP is one of them. There are many others in social media who did the same. Even those who I think are capable of separating the wheat from the chaff are equally irresponsible for spreading it.
Worse, they are putting words in BlackRock's mouth. This isn't BlacRock's opinion. This is not a study done by BlackRock. BlackRock has nothing to do with it. Those who started spreading this fake news are just using the huge brand to create a baseless FOMO.
