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BUCKET INVESTING With Dynamically Risk-Managed Portfolios By Tim Hanna, Ansh Chaudhary, and Jerry C. Wagner Flexible Plan Investments, Ltd. January 2021*
Summary We compare bucket investing to other common asset-allocation approaches—the traditional systematic withdrawal approach, in particular—for stocks and bonds. Our study analyzes some of the advantages and criticisms of the bucket investing approach. We conclude that using active management within the bucket approach can address some of the challenges of the method, which include sequence-of-returns and time-diversification issues. The bucket method with active management—specifically using different Multi-Strategy Core and Explore suitability profiles—shows the potential for much higher returns and can have greater psychological appeal to investors when compared to more traditional systematic withdrawal methods.
*Originally authored by Jerry C. Wagner, David Varadi, and Z. George Yang (September 2014). Jerry C. Wagner, J.D., is the founder and president of Flexible Plan Investments, Ltd., a U.S. registered investment advisory firm. The views and opinions are those of the authors only and do not necessarily represent those of Flexible Plan Investments or any of its affiliates. The authors are responsible for any errors. The authors also acknowledge the assistance of Renee Toth, Tiffany Wagner, and Jason Teed, and the programming assistance of Gayan Nagoda on data processing and statistics. The rise of bucket investing
It can be argued that the most important job for an investment adviser or financial planner is simply to protect investors from themselves. Creating an asset-allocation approach that can keep them invested and avoid selling risky investments at the wrong time is a difficult challenge. The “bucket” approach to investing has emerged as a popular asset-allocation methodology in the financial planning and advisory community because it is specifically designed to account for actual investor behavior.1
Designing an asset-allocation approach to meet a client’s financial objectives is often cited as the most important component of the investment advisory process. Despite the advent of Harry Markowitz’s modern portfolio theory, this process cannot be easily reduced to a financial engineering problem. Economists have long made a key assumption within their models that is highly flawed for the purposes of simplifying the mathematical implementation: They assume that human beings only make rational decisions.
Tim Maurer, a renowned financial adviser, speaker, and author, often states, “Personal finance is more personal than it is finance.” In that regard, economist Meir Statman has suggested that investors are neither irrational nor rational, but rather “normal”—that is, they display elements of both characteristics.2
The challenge of investor behavior
Empirical evidence has shown that investors are indeed far from rational. In a classic study by Dalbar, the average equity mutual fund investor made a return of 4.25%, while the S&P 500 made 6.02% over the same 20-year period. The 1.77% return differential could not be explained by financial theory and was famously dubbed “the behavior gap.” Investors lost over 60% of the returns available to them through poor market timing that was driven by emotional decision-making.3
The bucket investing approach seeks to address some of that emotional investor behavior with a combination of safety and a sense of control. It lets financial advisers set aside a portion of the investments to grow over time, assuring a steady income stream.4 Furthermore, it is highly compatible with the traditional financial-planning objectives that require matching assets to meet future liabilities.
What is bucket investing?
The bucket approach essentially divides a client’s portfolio assets into several pools, or “buckets.” Each bucket is assigned different planned goals, needs, or time horizons, and then a separate asset-allocation policy is designed for each. An individualized bucket approach also reflects financial planners’ and advisers’ emphasis on tailored solutions for their fee-paying clients.
Asset allocation using the bucket approach assigns each bucket a different asset type (such as bonds for income/capital preservation, or equities/stocks for capital appreciation). The simplest implementation of bucket investing would use only two buckets: bonds or cash to meet short- term expenses, and stocks for long-term growth5 (see illustration on the following page).
Bucket Investing | 800-347-3539 | flexibleplan.com 2 Different systems of bucket investing Simple Bucket Approach
Many different systems of bucket investing exist to address the specific needs and goals of different investors. Different tax brackets, opportunities to shelter income from taxation, unique planning objectives, and other factors all come into play. For example, some investors have relatively short-term objectives, while others may have longer- term goals such as saving for college tuition, retirement spending, or estate planning.
More complicated bucket strategies include those that use three to six buckets.6 Intermediate “buffer buckets” can have more refined planning time horizons designed for growth or spending goals and thus be targeted at layered return objectives. From an investment-management standpoint, a more complex bucket approach could use Wasting Bucket Approach different portfolios for each bucket, and these portfolios could be formed using either assets or strategies (or both) with either a passive or active management overlay.
Another example of a bucket approach commonly used by financial advisers is the “waterfall” bucket approach, in which the income bucket is replenished with flows from the longer-term buckets.
This study uses a “wasting” bucket approach whereby we drain the income bucket of its assets by withdrawing a fixed percentage annually for 10 years before turning to the stock bucket to generate the returns needed to make the annual withdrawal.
Common criticisms of the bucket investing approach
Though bucket investing addresses some of the negative investor behaviors previously described, it has drawn some criticism on its performance compared to other allocation strategies and for its capacity to manage risk over time and address sequence-of-returns risk.
Bucket Investing | 800-347-3539 | flexibleplan.com 3 Poor performance vs. static allocation strategies
A common criticism of the bucket approach is that it performs poorly when compared to static allocation strategies. However, many of the studies that advocate for one method or the other were conducted with a narrow set of historical data.7 Removing time-period biases leads to similar results under both strategies, which is illustrated by the case studies presented later in this paper.
Part of the reason the bucket approach has gained popularity in the investment advisory and planning community is the anecdotal evidence from peers that it improves client communication and retention. Behavioral finance proponents attribute this success mainly to the fact that most investors have a “mental accounting” bias.
Paraphrased from academic researcher Richard Thaler, who first coined the term, “mental accounting” describes a person’s tendency to categorize and evaluate economic outcomes by grouping their assets into a number of nonfungible (distinct) “mental accounts.”8 People may alter their perspective on money and investment according to the surrounding circumstances and make irrational decisions due to such a framing bias.
Behavioral life-cycle theory states that people mentally allocate wealth across three classifications: current income, current assets, and future income. As people tend to prefer spending now, rather than saving for later, the time-horizon-based bucket approach for wealth management was designed to address the psychological need for investors to have near-term liquidity, as well as continue working toward the goal of long-term growth of wealth.9
In practice, a floor level of assets designated as a short-term “spending bucket” is often kept as cash or in short-term securities that have little or no investment risk. Further, from a portfolio management perspective, planning “buckets” of capital under the framework of “goals-based investing”10 does institute beneficial risk discipline into the investment process.
Time diversification is a myth
One supposed benefit of using the bucket approach is that it aims to provide “time diversification.” According to the concept of time diversification, investments in higher-risk assets (such as stocks) are less risky over longer periods than shorter ones.
In a traditional two-bucket approach, the least-risky asset—typically, short-term bonds—is held in the bucket used to service immediate income needs. Meanwhile, the riskier portion of the portfolio—typically invested in stocks—is held in the bucket used for longer-term growth and aims to stay invested for a sufficient time to overcome any “bad luck” in terms of the start date (i.e., beginning of a bear versus the start of a bull market).
Some in the academic community debate the assertion that sufficient time will reduce the riskiness of stocks (see, for example, “What Practitioners Need to Know … About Time Diversification” by Mark Kritzman, “Stocks for the Long-Run” by Jeremy Siegel, and “The Long-Term Case for Equities—and How It Can Be Oversold” by Paul Samuelson). However, the numbers and the math are fairly straightforward and suggest that this matter is much more settled than in question.
Bucket Investing | 800-347-3539 | flexibleplan.com 4 Kritzman notes that the key point of confusion is that the probability of losing money—which is mathematically and empirically supported to be lower over time—does not consider the magnitude of the potential losses. Like any investment, the “expectation” is a function of both the probability of winning or losing and the ratio of the size of profits to losses. The dispersion of compound return percentages does shrink over time, but the variability of ending portfolio wealth (terminal wealth—the dollar value) actually increases over time.11 All of this is captured in financial options theory and pricing—and, in fact, the cost of option premiums does increase over time, which reflects the truth that time diversification is illusory.12 Failure to understand this can lead to some faulty construction of the longer-term buckets.
To illustrate this concept, we performed a series of Monte Carlo simulations using Brownian motion, which is a typically accepted practice for modeling a financial time series. Figure 1 shows the distribution of compound returns for five-year simulations, assuming that the market has a return of 8% and a standard deviation of 20%. We performed 25,000 simulations.
Figure 1 Distribution of Compound Returns for a 5-Year Stock Simulation
Source: Flexible Plan Investments Research
Notice that there is considerable variability when holding stocks for such a short time period. While the distribution is skewed, the absolute values of the maximum and minimum return values are nearly identical.
Subsequently, we performed a simulation using a long time period instead. In this case, to make the results clear, we chose 100 years (Figure 2).
Bucket Investing | 800-347-3539 | flexibleplan.com 5 Figure 2 Distribution of Compound Returns for a 100-Year Stock Simulation
The Spread Narrows
Source: Flexible Plan Investments Research It is easy to see that, as more time passes, returns at almost every point in the distribution become positive.
The problem is that investors do not get 100-year returns. Instead, they must compound them over a shorter time period. In other words, every year they must, in effect, re-invest their portfolio and have their entire wealth fluctuate as a function of the next year’s investment return. This is why risk management is so important, because a 50% loss can erase more than 10 years of investment gains.
In the next set of simulations, we show the distribution of terminal wealth (ending portfolio wealth) as a function of an investor’s holding period using the same set of assumptions.
Dispersion of terminal wealth for simulated stock time series
Figure 3 $100,000 “Grows” to Ending Balance Over 5-Year Holding Period
Source: Flexible Plan Investments Research
Bucket Investing | 800-347-3539 | flexibleplan.com 6 Figure 4 Distribution of Terminal Wealth 20-Year Holding Period
The Spread Widens
Source: Flexible Plan Investments Research
Figure 5 Distribution of Terminal Wealth 100-Year Holding Period
The Spread Gets Even Wider
Source: Flexible Plan Investments Research
Notice that the maximum terminal wealth is just over $750,000, while the minimum is close to $20,000. For comparison, we ran the same study using a 20-year and then a 100-year time frame (Figures 4 and 5).
In both the 20-year and 100-year holding periods, there are multiple instances of portfolios that have an ending wealth that is below $10,000 (i.e., a loss of more than 90%), and in some cases close to zero! Of course, the magnitude of the possible gains is also substantially higher than for the five-year portfolio, with billions of dollars being earned in the 100-year portfolio in some cases.
The variation in the outcomes of terminal wealth increases substantially over time, but the center of the distribution of terminal wealth outcomes tends to shift higher the longer the holding period. This highlights how a longer holding period tends to increase the likelihood of higher terminal wealth and decrease the likelihood of the portfolio experiencing a loss.
Bucket Investing | 800-347-3539 | flexibleplan.com 7 The “sequence of returns” dilemma
The sequence of returns is essential to Table 1 A simulation of asset allocation determining ending portfolio wealth and over time for the bucket approach whether or not an investor will be successful in achieving desired results. Finance professor Moshe Milevsky claims in his article “Can Buckets Bail-Out a Poor Sequence of Investment Returns?” that using the bucket approach or any other type of time-based asset-allocation methodology is, in fact, just an illusion.13
Using the bucket approach cannot protect an investor from a poor sequence of returns; although, it can potentially shift the risk to a different point in time, depending on when the investor is most exposed to equities.
The key point that Milevsky makes is that, without doing more, the asset allocation of an investor using the bucket methodology will change substantially over time. For example, in Table 1, we perform a 20-year simulation with stocks and bonds with a 4% withdrawal rate using a two-bucket approach, with each bucket given a 10-year time horizon.
Starting with a 50/50 portfolio of stocks and bonds, the bucket investor eventually shifts to 100% stocks. In this simulation, the average allocation was actually 77% in stocks and 23% in bonds—which is a significant departure from the original 50/50 portfolio. The actual average asset allocation and timing of the shifts will depend on the underlying market performance, the number of buckets, and the length of each bucket’s Source: Flexible Plan Investments Research. Assumes an 8% compound annual growth rate (CAGR) and a 20% standard deviation for the stock time horizon. basket and a 5% CAGR and 6% standard deviation for the bond basket. Correlation was assumed to be zero and 4% was withdrawn annually. 25,000 simulations were performed. This implies that the bucket approach is not easily comparable to a withdrawal strategy with, for example, a constantly rebalanced portfolio. However, as a general statement, the bucket approach is most exposed to equity risk at the end of the period and somewhat less exposed to risk at the beginning of the investment period.
Bucket Investing | 800-347-3539 | flexibleplan.com 8 At the outset, withdrawals will be taken from the less risky asset and therefore create less dependency on equity volatility than a systematic withdrawal approach from a constantly rebalanced portfolio. This can present problems, depending on when equity or fixed-income risk increase and losses are incurred.
A solution to address this criticism, which is discussed later in this paper, would be to use actively managed buckets, in which the overall exposure in each bucket mimics that of stocks and bonds, but the actively managed strategies help to reduce the exposure to risk during volatile periods, reducing the “sequence of returns” risk more than a passive allocation to equities and bonds would potentially produce.
Case studies: Simulations of the bucket approach versus systematic withdrawal methods
To better illustrate the benefits of using a bucket approach over a traditional asset-allocation approach, and counter some of the criticisms of the bucket approach, we ran a series of case studies using Monte Carlo simulations.
We compare three basic methods:
1. A simple two-bucket approach (50% in bonds for the first bucket and 50% in stocks for the second bucket) where the first bucket was liquidated and shifted to the next bucket at the end of its respective time horizon. We chose 10 years as the time horizon for each bucket. 2. A systematic withdrawal (SW) approach that assumes a constantly rebalanced portfolio fixed at 50% in stocks and 50% in bonds. 3. A systematic-withdrawal time-weighted (SW/TW) approach designed to be more comparable to the average asset allocation of the bucket approach. We used 2/3 in stocks and 1/3 in bonds in this approach to reflect the fact that the bucket method has an investment in the stock portfolio that is twice as long as the investment in bonds.
We made the following assumptions, which we believe to be reasonable from a historical standpoint:
• That stocks would have an 8% return with a 20% standard deviation. • That bonds would have a 5% return and a 6% standard deviation. • That the correlation between stocks and bonds was zero. • That the investor would withdraw 4% annually for a total time period of 20 years.
Using the bucket approach, each bucket lasted 10 years; the first bucket contained bonds, and the second contained stocks. To make accurate conclusions, we ran 25,000 different simulations and averaged the results.
One of the key metrics that we used to evaluate “success” for the investor was the Omega statistic (for more about the Omega statistic, see “A Universal Performance Measure” by Con Keating and William Shadwick, as well as the Appendix at the end of this paper). This statistic is used in option pricing and is a comprehensive risk measure that captures the upside versus the downside given a threshold return. The Omega ratio is a relative measure of the likelihood
Bucket Investing | 800-347-3539 | flexibleplan.com 9 of achieving a given return, such as a minimum acceptable return or a target return (see the Appendix for a deeper discussion of the Omega ratio and the formula we used to calculate it).
For our simulations, we randomly generated one-year returns until we had a 20-year sample. To calculate Omega, we used the annualized returns of each simulation as returns in the inputs into the function.
Base case: Bucket approach identical to systematic withdrawal using the same asset class
For a base case (Table 2), we wanted to see if there was any difference between the bucket approach and systematic withdrawal under the assumption that one uses the same asset in each bucket. If there is no difference, this implies that creating different time horizons or liquidation schedules has no impact on performance. In all cases, “ATV” represents the average terminal value and “MAR” represents the annualized return relative to the maximum drawdown (MDD).
Table 2 Base Case Example: 10% Return/10% Risk and 5% Withdrawal
Same Asset Used in Bucket and SW