Bitcoin’s role in an investment portfolio

By   James Butterfill 8th September 2020

Conventional wisdom is that bitcoin has had great returns but it does that by adding substantial risk (volatility) to a traditional equity/bond portfolio.

However, our research has found that:

  • Small weightings of bitcoin have an outsized positive impact on risk-adjusted returns and diversification relative to other alternative assets.
  • Bitcoin’s lack of correlation to other assets make it a useful alternative asset that can help reduce exposure to economic cycles.
  • Quarterly adjustments (rebalancing) of Bitcoin, back to the original weight in the portfolio can help limit volatility and enhance returns.

Bitcoin’s journey over the last decade has been well documented, with supporters and sceptics alike jostling to comment on the price of the world’s largest public blockchain. For investors with long-term investment horizons, however, a fundamental question remains largely unanswered: what is the effect of including bitcoin in an investment portfolio?

We believe thorough analysis of how Bitcoin performs in a typical 60/40 equity/bond portfolio is necessary to determine if it genuinely enhances or detracts from overall performance and diversification.

The analysis we carried out highlights that Bitcoin not only enhances returns, but also increases diversification regardless of when an investor decided to invest.

The Effect of Bitcoin on an Investment Portfolio - The Data

To test how bitcoin would help or hinder a portfolio we created a database of daily returns starting from 2015 when it was first financialised (available as an ETP). We created a traditional balanced portfolio with 60% equities and 40% bonds and then added a modest amount of bitcoin, detracting from both equities and bonds equally.

As bitcoin is an asset in an early growth phase, most investors would allow its portfolio weight to drift to some extent. We decided to rebalance on a quarterly basis, despite its potential hindrance on enhancing returns, because we believe rebalancing helps moderate volatility.

Bitcoin Improves Investment Portfolio Performance

Despite bitcoin’s volatility, an allocation of 4% to the aforementioned portfolio improved annualised returns from 9.3% to 18.8%.

The Sharpe ratio of an investment portfolio tells us how good or bad returns have been relative to the risk taken on by the investor. Usually, any Sharpe ratio above 1 is considered to have a positive impact on a portfolio.

In this case we see a Sharpe ratio of 1.69 while the correlation to the base portfolio falls significantly by 15%:

Data derived from a balanced 60/40 quity/bond portfolio, with an equal weight detraction to allocate to bitcoin, gold, SOCL or the CRB. XBTUSD, Gold, SOCL and CRB indices are used. Rebalanced per calendar quarter.

Bitcoin Performance vs Various Asset Classes in a Portfolio

Bitcoin has been a diversifier for the standard 60/40 portfolio over the last three years. But, there are other alternative assets that might be used as diversifiers. We sought to understand how bitcoin has performed against these other alternatives.

We included in our analysis:

  • Gold due to bitcoin being often likened digital gold.
  • The SOCL index, a social networking index (including companies such as Facebook and Google) as bitcoin has been more closely correlated to this equity index than others in recent years.
  • Finally, the CRB index, a representative indicator of today’s global commodity markets due to its similarities to commodities.

What is striking, is that over the same period none of the other comparable assets or indices offer the same diversification benefits. What also makes bitcoin stand out is its asymmetric return profile, that is, the upside it provided versus the downside. Despite bitcoin’s volatility, a 4% portfolio weighting does not materially increase the maximum drawdowns (i.e. the maximum possible loss from peak to trough) relative to other assets, while its annualised returns are close to double that of the other alternatives.