Introducing the Bear Market Damage Index

CIO Global Blog

12 Aug 2019

Erratum: This version corrects the "Longest plateau time" statistic in Table 1 and in the text. Please disregard the earlier version published on 8 August 2019.

When an investor is forced to sell out of their portfolio during a market drawdown, they not only lock in otherwise-temporary losses, but they also prevent their assets from fully participating in the market recovery (and future gains). For unprepared investors, unfortunate timing—for example, a sizable market drop at the beginning of retirement—can catastrophically deplete investment portfolios.

This dynamic is referred to as sequence-of-returns risk, or "sequence risk," and it is a potent danger for retirees who are committed to pulling capital from their invested assets regardless of market conditions. The potential damage caused by sequence risk can be difficult to quantify because there are a lot of variables to consider, but this is a useful concept to evaluate the efficacy of strategies that can mitigate sequence risk.

Assuming the worst: building a "Super bear market"

We begin by simulating a "worst-case" bear market for different stock/ bond portfolios. We accomplish this by looking at the statistics from each of the seven post-war bear markets from our Bear market guidebook, and combining their worst characteristics—the largest and fastest drawdown and the longest and slowest recovery time—to produce a "super bear market" for each portfolio.

These "super bear markets" comprise three sections: the drawdown period, where the portfolio quickly goes from peak to trough; the plateau, where the portfolio stays at its trough value for months; and then the recovery period, where the portfolio endures a very slow-but-steady rally from the trough back to a new all-time high.

Next, to accentuate the potential sequence risk in the simulation, we assume that the bear market begins at the worst possible time: at the beginning of retirement. To create a baseline Bear Market Damage Index, we assume a 4% annual withdrawal rate (taken monthly), along with a 2% annual spending increase to approximate a rising cost of living due to inflation.

The Bear Market Damage Index

To calculate each portfolio's BMDI, we run a simulation of the portfolio's value after withdrawals up until the end of the longest-ever bear market window. At this point, the portfolio would have recovered back to a new all-time high without spending, but the spending has significantly depleted the portfolio value and locked in bear market losses.

BMDI is calculated as the percentage of the portfolio's depletion, indexed to 100. For example, a USD 1 million all-equity portfolio would have experienced a 51% drawdown over the course of 3 months, and spent about 22 months at the plateau, before beginning the 49-month climb back to a new all-time high, resulting in a "bear market window" (time from peak to peak) of 74 months.

An investor would have spent about USD 258,383 during this window, and without any capital set aside in a Liquidity strategy to meet cash flow needs, they would have locked in another USD 158,106 of losses due to sequence risk. Therefore, the BMDI for this portfolio is 42 (USD 1,000,000 starting value, minus the ending value of USD 583,511, divided by the USD 1,000,000 starting value, multiplied by 100). With a 74-month Liquidity strategy allocated at the beginning, the investor would have been able to avoid locking in any losses, resulting in a BMDI of just 26 (USD 1,000,000 starting value, minus the ending value of USD 741,617, divided by the USD 1,000,000 starting value, multiplied by 100).

Figure 1 - Illustrating a "Super bear market"

Growth of USD 1,000,000

100% stock, 0% bond portfolio

Source: UBS, MorningstarDirect



The table below shows the "Super bear market" statistics and baseline BMDI values for each simple stock-bond mix, demonstrating the importance of a sufficiently funded Liquidity strategy and the importance of owning sufficient fixed income to help manage bear market damage.

Table 1 - There are two keys to managing bear market damage: a sufficiently-funded Liquidity strategy and a healthy allocation to bonds

Source: UBS, MorningstarDirect

Manage risk, but also opportunity cost

Of course, bear market risk is only one side of the coin. As we discuss in "The difference between pain and damage (PDF, 194 KB)," taking too little risk can cause just as much damage as taking too much. For example, a Liquidity strategy does not need to be funded solely from the asset side of the balance sheet, and investors that are willing to borrow to meet some of their cash needs can manage bear market risk with less opportunity cost (foregone gains) during bull markets. Finding the right balance is crucial, so make sure your bear market plan considers both sides of the coin.


Justin Waring, Investment Strategist Americas, UBS Financial Services Inc. (UBS FS); Michael Crook, Head Americas Investment Strategy, UBS Financial Services Inc. (UBS FS)