BlackRock 2% Bitcoin cap may force adviser sales

BlackRock Investment Institute recommends a 1% to 2% Bitcoin allocation for multi-asset model portfolios. When advisers set a hard 2% cap, sizeable Bitcoin rallies can push the allocation above target and force portfolio rebalancing decisions.

BlackRock sizes Bitcoin positions by contribution to total portfolio risk. According to the firm’s calculations, a 1% Bitcoin sleeve adds about 2% to overall portfolio risk, a 2% sleeve adds about 5%, and a 4% sleeve adds about 14% inside a standard 60/40 mix. Under those assumptions, a 2% Bitcoin position would drift to roughly 3% after about a 51.5% Bitcoin gain with the rest of the portfolio flat, and to about 4% after roughly a 104% gain. Resetting a 4% sleeve back to 2% would require selling nearly half the Bitcoin holding.

Market flows have increased the scale of those choices. BlackRock’s iShares Bitcoin Trust had nearly $60 billion in net flows as of July 2. U.S.-traded spot Bitcoin ETFs lost more than $2.7 billion across a 10-day span in late June through July 1. The Options Clearing Corporation reported 689.5 million ETF options contracts traded in June, up about 70% year over year, and options open interest tied to one large spot Bitcoin ETF peaked at roughly $53.3 billion in its first year. A major bank reduced its 12-month Bitcoin price target to $82,000 from $112,000 and lowered its ETF inflow assumption to zero.

Advisers have tools to limit sales when a sleeve exceeds a cap. They can set wider tolerance bands around the target, use new client contributions to rebalance, place Bitcoin exposure in tax-advantaged accounts such as IRAs or Roths to avoid immediate tax bills on trims, or overlay options strategies such as covered calls or collars to generate income or buy downside protection while keeping the underlying position.

Borrowing against Bitcoin is an alternative to selling. Mauricio Di Bartolomeo, co-founder and chief strategy officer at Bitcoin lender Ledn, described borrowers as a mix of companies, households and individual investors that often prefer financing to outright sales to retain an asset they consider a core holding. He advised that borrowers set aside about 100% of collateral value to absorb market swings and cautioned that borrowing beyond half of a Bitcoin portfolio reduces the cushion against sharp price drops.

Kelly Ye, co-founder and chief investment officer at CoinBridge, noted that a large share of current Bitcoin ETF activity remains self-directed on major platforms, with roughly one-fifth routed through advisers. She added that large wirehouses typically require six to 12 months of performance history and operational checks before adding a new ETF to a centralized model.

Industry developments include new structured products that pair Bitcoin exposure with options income strategies. Assets tracking third-party model portfolios grew from about $400 billion in 2023 to over $645 billion in 2025, expanding the infrastructure that can translate model rules into market flows.

BlackRock frames a 1%–2% allocation as reasonable for investors who expect continued adoption of Bitcoin and can tolerate sharp drops. For advisers and platforms that keep a strict 2% ceiling, the combination of ETF scale, rebalancing rules, tax location and lending options influences whether rallies lead to sales or are managed without selling.