BlackRock said in its latest report, Re-Underwriting Bitcoin: Still a Portfolio Diversifier, that a 1% to 2% BTC allocation remains the range that matters most for institutions willing and able to bear Bitcoin risk. The report does not treat Bitcoin’s roughly 50% decline from its October 2025 peak as a final judgment on the asset. It goes back to the portfolio question that allocators actually care about: what Bitcoin does to risk and return once it is placed inside a diversified portfolio.
The study’s main focus is not Bitcoin’s standalone price swings. It is a re-test of earlier assumptions after a deep drawdown. BlackRock’s point is that the useful signal comes after a large decline, when investors can revisit which parts of the institutional Bitcoin story were structural and which were tied to a specific market cycle.
Backtests show higher returns with limited additional portfolio volatility
In rolling 10-year backtests through May 29, 2026, a traditional 60/40 stock-bond portfolio produced annualized returns of about 9.9% with annualized volatility of about 10.1%, according to BlackRock. Adding a 1% Bitcoin allocation lifted annualized returns to about 10.9%, while volatility edged up only slightly to about 10.3%. With a 2% allocation, annualized returns rose to about 11.8% and standard deviation reached about 10.6%.
That means a 2% Bitcoin position added about 190 basis points of annualized return relative to the traditional portfolio, while increasing annualized portfolio volatility by only about 50 basis points. Over the same comparison, the Sharpe ratio improved from 0.81 to 0.96, and maximum drawdown changed from -20.3% to -20.9%.
BlackRock said these are backward-looking simulations, not promises about future performance. Still, the numbers show why judging Bitcoin only by its own volatility can miss its effect at the portfolio level. For allocators, the more important issue is how Bitcoin interacts with assets they already hold.
BlackRock argues the correlation spike is cyclical rather than permanent
The firm continues to frame Bitcoin’s risk and return drivers as fundamentally different from those of traditional assets. BlackRock points to Bitcoin’s fixed supply, decentralized design, and lack of dependence on any sovereign issuer. That does not stop it from falling alongside risk assets during deleveraging episodes, but the report says such high correlation is more likely a phase than a permanent structure.
That is why a small allocation does not transfer Bitcoin’s standalone volatility into a portfolio on a one-for-one basis. The central calculation is what investors historically received in return for taking on that extra marginal risk. Even after including the latest major drawdown, BlackRock said the trade-off still worked at 1% and 2% position sizes.
The 1% to 2% range is not new, and it is not presented as optimal
BlackRock has discussed this range before from a risk-contribution angle. For investors who can tolerate Bitcoin risk, the firm has said 1% to 2% is a relatively reasonable band. At those weights, Bitcoin’s contribution to total portfolio risk is broadly comparable to that of a single large-cap technology stock inside a traditional 60/40 allocation. Beyond 2%, the report said, Bitcoin’s contribution to total risk rises disproportionately.
The new report runs the exercise from the opposite direction. Instead of asking how much risk Bitcoin adds, it asks what investors historically received for taking on that added risk. On that basis, the traditional portfolio’s Sharpe ratio of 0.81 rose to 0.90 with a 1% Bitcoin allocation and to 0.96 with a 2% allocation. BlackRock’s conclusion is that the incremental return historically covered the extra volatility at the portfolio level.
Even so, the firm did not describe 1% or 2% as the best allocation. It said appropriate exposure depends on liquidity needs, investment horizon, governance constraints, and risk tolerance. The value of the report, in BlackRock’s framing, is that it offers a harder framework for the conversation: institutions can assess Bitcoin positions through marginal risk, correlation, drawdown, and portfolio efficiency instead of stopping at a binary debate over whether Bitcoin is too volatile to touch.
IBIT provides the demand-side backdrop
BlackRock’s own product history also forms part of the context. The iShares Bitcoin Trust, IBIT, launched in January 2024 and surpassed $50 billion in assets in less than a year. BlackRock described it as the largest ETF launch in history, with a growth pace roughly five times that of the previous record holder.
IBIT was later described as the world’s largest and most actively traded Bitcoin ETP. In 2025, it became BlackRock’s highest-revenue ETF despite the company running more than 1,000 products globally.
Holdings in U.S. spot Bitcoin ETFs are also concentrated. Data tracked by Bitcoin For Corporations shows U.S. spot Bitcoin ETFs collectively hold about 1.25 million BTC, close to 6% of Bitcoin’s fixed 21 million supply. IBIT alone holds about 775,000 BTC, accounting for more than 60% of the Bitcoin held by U.S. spot ETF products.
That does not remove the commercial context from BlackRock’s research. IBIT has become increasingly important to the firm. At the same time, it means this “re-underwriting” comes after institutions have already spent more than two years holding Bitcoin exposure through familiar brokerage, advisory, and institutional channels, across both a rally and a deep drawdown. IBIT’s continued growth also suggests demand did not end with the launch window.
The report arrived after a major pullback, not at the top
The timing matters. BlackRock revisited Bitcoin after it had fallen about 50% from its October 2025 high, not while it was setting records. The firm attributed that stretch to leverage being flushed out, slower ETP inflows, and weaker corporate treasury demand for Bitcoin. Its conclusion was that the market saw a position reset rather than a breakdown in the investment case.
BlackRock’s argument is that an investment thesis should survive changing conditions if its underlying assumptions still hold. For Bitcoin, those assumptions go beyond historical returns. The report points to scarcity by design, global tradability, independence from sovereign issuers, and a structure that differs from the liability-heavy makeup that dominates traditional portfolios. BlackRock also said fiscal sustainability, monetary stability, and geopolitical risk may become increasingly relevant to Bitcoin’s long-term adoption.
Institutional discussion is shifting from whether to own Bitcoin to how much to own
The report does not claim that portfolio backtests can prove the next decade’s returns, and IBIT’s product success does not settle the question of how much Bitcoin any institution should hold. Taken together, though, the two points show how the conversation has moved. Bitcoin is no longer discussed only as an optional alternative asset. It is increasingly being assessed under the same discipline applied to other assets: position sizing, risk contribution, correlation, liquidity, drawdown, and expected return.
For management teams, BlackRock’s framework suggests the question is not whether Bitcoin is volatile. That is already well understood. Nor does a corporate allocation need to become an extreme strategy that ties the capital structure to Bitcoin. There is a wide range between zero exposure and a Bitcoin-heavy balance sheet.
In BlackRock’s framework, a relatively small allocation can materially improve the historical return profile of a traditional portfolio without raising total portfolio risk in the same proportion. Within the range studied, a 2% allocation added about 190 basis points of annualized return while increasing annualized portfolio volatility by only about 50 basis points.
For corporate decision-makers, the practical takeaway is not to copy BlackRock’s numbers mechanically. It is to apply the same discipline: define the purpose of the allocation, set an acceptable level of risk contribution, establish liquidity and governance requirements, size the position accordingly, and revisit the assumptions over time.
After another full cycle and a drawdown of about 50%, BlackRock has re-underwritten the question and reached the same broad answer in historical portfolio terms: within a controlled size, Bitcoin can improve the equation.