Is Crypto a Good Gift for Your 60/40 Portfolio?

The holiday season is a time of giving, and investors are searching for the perfect gift to give their portfolios. While the classic 60/40 mix of stocks and bonds has long been a staple, the rise of cryptocurrency is tempting many to add a little digital sparkle to their investment strategy, especially after the Securities and Exchange Commission approved 11 spot bitcoin exchange-traded funds and nine spot ethereum ETFs in 2024. But is crypto the festive upgrade your portfolio needs, or just a flashy stocking stuffer best left on the shelf? The crypto market recently experienced a sharp selloff, reminding everyone of its volatility. For example, iShares Bitcoin Trust ETF IBIT fell 26% from its October peak through Dec. 10 and turned negative for the year all while stocks largely continue to climb. So, before wrapping it up and putting it under the tree, investors should understand crypto’s potential impact on their portfolio.

Spot Bitcoin and Ether ETFs Were an Instant Hit

The SEC’s approval of spot bitcoin and ether ETFs made it easier than ever for investors to access the two largest cryptocurrencies. Now, investors can also find ETFs that track the spot price of other popular digital currencies such as solana, XRP, and even dogecoin. Crypto ETFs have spurred broader adoption and recognition. Even Vanguard—initially resistant to crypto ETFs—began allowing access to four third-party spot bitcoin ETFs on its brokerage platform as of December 2025.

Periods of high returns for cryptocurrencies like bitcoin have turned the heads of many investors, and it’s no surprise that they have poured assets into the ETFs over their relatively short lives so far. Spot bitcoin and ether ETFs grew to $114.8 billion and $19.1 billion since launching in January and June 2024, respectively, through November 2025, despite big outflows in November alongside the recent crypto dive. They raked in a combined $69.3 billion over the period, exhibiting the strong investor demand for crypto, though, the evidence so far shows investor flows follow performance.

Diamond Hands Required

Exceptional returns for the ETFs have contributed to strong demand. For example, iShares Bitcoin ETF gained 44% since it launched in January 2024 through November 2025 compared with the S&P 500, which returned 23% over that same period, though, investor returns in the ETF may be different. While the ETFs’ returns represent a noticeable premium over large-cap US stocks, booms and busts have checkered crypto’s short lifespan so far, requiring investors to stomach heightened volatility.

The exhibit below highlights that bitcoin and ether have consistently been much more volatile than a classic 60/40 stock/bond portfolio. It compares the rolling one-year standard deviation—a measure of volatility—of bitcoin, ether, and a traditional 60/40 portfolio since May 2016, using monthly returns from the S&P Bitcoin Index, S&P ethereum Index, and a 60/40 portfolio composed of the Morningstar Global Markets Index and Morningstar US Core Bond Index, rebalanced monthly. While volatility has trended downward over time, it’s no guarantee that trend will continue. Bitcoin and ether have been 8 and 12 times more volatile than the 60/40 portfolio, on average, over the period. Crypto’s extreme volatility has tested even the staunchest enthusiasts, and some investors may not possess the diamond hands required.

Crypto Changes the 60/40 Portfolio’s Risk Profile

Just because an asset holds a certain weight doesn’t mean the risk it contributes to the portfolio is equivalent. For example, stocks are more volatile than bonds, so the risk they contribute to a 60/40 portfolio is typically closer to 80%. Crypto, which is even more volatile than equities, can also have a disproportionately large impact on a portfolio’s overall risk profile. A little bit can go a long way, as illustrated in the exhibit below. It depicts bitcoin and ether’s risk contribution to the 60/40 portfolio when holding bitcoin, ether, and a 50/50 blend of the two at various weights (1%, 2%, 5%, 10%, and 25%) assuming the crypto is sourced from the stock sleeve (funding something as volatile as cryptocurrency from bonds is not a good idea). The next exhibit shows how each hypothetical portfolio’s standard deviation changed over the period, given the varying allocations to bitcoin.

The results are staggering. While bite-sized 1% or 2% allocations to crypto may not noticeably impact overall portfolio volatility, ether, bitcoin, and a blend of the two still contribute disproportionately to total risk, accounting for 3%-5% and 7%-13% to total risk at 1% and 2% weights, respectively, as shown in the exhibit below. Ether has historically been more volatile than bitcoin, so it contributes more to risk.

Be Wary of What Lies Beyond 5%

Investors often wonder what the “right” allocation to crypto is. The decision is personal and the question of how much, if even to allocate at all, depends on an investor’s risk tolerance. As the exhibits above show, 5% is a critical juncture where the risk profile of the portfolio meaningfully starts to change. At that level, a 50/50 bitcoin/ether split contributes 27% of the portfolio’s total risk and the overall volatility is 1.3 times that of the baseline 60/40 portfolio. Investors should ask themselves if they are comfortable with 30% more volatility in their portfolio for a 5% stake in crypto.

Going beyond a 5% allocation is where things can get wild. At 10%, the blended crypto allocation occupies over 50% of the portfolio’s total risk while a 25% weight takes that number up to a whopping 87%. The portfolio with a 25% crypto allocation is also more than twice as volatile as the standard 60/40 portfolio, so investors allocating that much require nerves of steel.

Crypto as an asset class is quite volatile, but does adding more than one help diversify some of the risk away? Ether has historically been more volatile than bitcoin, therefore contributing more to risk and overall portfolio volatility than investing in bitcoin alone or a mix of the two, as the exhibits above illustrate. The blended allocation falls between ether and bitcoin in terms of risk contribution and overall volatility, suggesting there may be some diversification benefit, especially at higher weights. That said, crypto is a volatile asset class, so investors should expect any combination of cryptocurrencies to disproportionately impact the risk of their portfolio.

Higher Returns, Higher Risk

The exhibit below shows returns of portfolios with 1% to 25% exposures to a 50/50 basket of bitcoin and ether sourced from the equity sleeve from May 2016 through November 2025. Simply put, the higher the allocation to crypto, the higher the return of the portfolio. Curiously, despite bitcoin and ether’s wild volatilities, their returns were so high that volatility-adjusted returns measured by the Sharpe and Sortino ratios were higher for the crypto portfolios than the baseline 60/40. But taking a closer look reveals some cracks, like the 25% crypto allocation portfolio holding a similar Sharpe ratio to the 10% portfolio, which suggests diminishing marginal risk-adjusted returns at higher allocations of crypto. This study also assumes monthly rebalancing, so one would be theoretically buying low and selling high. Most importantly, it also assumes holding on to both cryptos during their many drawdowns, requiring the sturdiest of diamond hands. The portfolio with a 25% blended crypto allocation experienced a maximum drawdown for the period of 35%, 11 percentage points more than the 60/40 portfolio’s.

Does Rebalancing Frequency Matter?

Rebalancing frequency can impact outcomes. Portfolios tend to drift over time from their target allocations and regular rebalancing can help manage risk while keeping the portfolio in line with an investor’s goals. Rebalancing is especially important for volatile asset classes like crypto since its weight in the portfolio could dramatically shift over time and lead to unintended consequences, such as a disproportionately large allocation.

The exhibit below shows risk and returns metrics from May 2016 through November 2025 for a portfolio that allocated 5% to a 50/50 mix of bitcoin and ether. If an investor bought and held the two without any portfolio rebalancing, they would have received a higher return than if they regularly rebalanced; that return is double what they would have received had they rebalanced monthly. That said, they would have experienced the largest drawdown (59.5%!) and lowest risk-adjusted returns measured by the Sharpe and Sortino ratios. Semiannual and quarterly rebalancing scored the highest Sharpe ratios while annual rebalancing sports the highest Sortino ratio, which focuses only on downside volatility. The evidence shows that while investors would have received the highest return if they didn’t touch their crypto-infused portfolio, periodic rebalancing is critical to managing the portfolio’s risk.

More to It Than Volatility

Volatility tends to grab the headlines, but correlation is another key tenet of portfolio construction that shouldn’t be ignored when allocating to crypto. It was once thought that crypto could offer returns uncorrelated to both stocks and bonds. So far, that hasn’t been the case, especially for equities. The exhibit below shows rolling one-year correlations using monthly returns of a 50/50 mix of bitcoin and ether to global public equities, US technology stocks, and bonds.

The Verdict?

Sometimes less is more when giving gifts, and investors would do well to keep that in mind if considering crypto for their portfolios. While a small amount could add some excitement and potentially boost returns, crypto’s heightened volatility could send shivers through the portfolio. Before allocating, investors should understand that crypto’s extreme volatility can drastically alter their portfolio’s risk profile and allocating too much could cause it to stray from an investor’s goals and risk tolerance.