The Rational Reminder Podcast
The Rational Reminder Podcast

Episode 383: AMA #10 - Dollar cost averaging & mutual funds vs. ETFs

In this episode of Rational Reminder, Ben Felix, Cameron Passmore, and Ben Wilson return with a classic AMA format—answering listener questions that dig deep into the behavioral and evidence-based foundations of sensible investing. From lump-sum investing to the psychology of advice, the trio blend

Featured Speakers

Benjamin Felix, Cameron Passmore, and Dan Bortolotti Host

Topics Discussed

Episode Summary

Executive Summary: Episode 383 is an AMA covering investing fundamentals and product structure. The hosts discuss why lump-sum investing generally beats dollar-cost averaging, how advisor value comes from base rates and behavioral coaching, why Dimensional stays in mutual funds in Canada, tax effects on discount bonds, the shortcomings of buffer ETFs, and why the Rational Reminder model portfolio remains intentionally simple despite new factor ETF options.

Main Topics: Lump Sum vs. Dollar-Cost Averaging: The hosts explain that lump-sum investing usually outperforms dollar-cost averaging, with DCA mainly justified by behavioral regret reduction rather than expected return. They emphasize that the decision should be framed around base rates and risk-appropriate asset allocation. Advisor Value, Base Rates, and Behavioral Coaching: They argue that advisors add value by providing decision base rates, preventing costly mistakes, and coaching clients through volatility. Even smaller-net-worth investors can benefit from fee-only advice or technology-enabled support, though the hosts remain skeptical of AI replacing human judgment. Dimensional Mutual Funds vs. ETFs in Canada: The episode explains why Dimensional has maintained mutual funds in Canada: unlike the U.S., Canadian tax rules can make mutual funds at least as tax-efficient or more tax-efficient than ETFs because of the Capital Gains Refund Mechanism and redemption patterns. Tax Efficiency of Discount Bonds: The hosts address whether lower-coupon discount bonds are priced efficiently after tax. They conclude that, in Canada, discount bonds still appear more tax-advantaged for taxable investors and that this benefit does not seem fully arbitraged away. Buffer Funds and Structured Products: They review buffer ETFs as option-based products that cap upside and limit downside, but cite evidence that these structures often underperform simpler stock/cash alternatives on a risk-adjusted basis and may be more marketing-driven than investor-driven. Rational Reminder Model Portfolio and Simplicity: The hosts defend not constantly updating the RR model portfolio, noting there is no single optimal portfolio and that the current design remains a reasonable, simple implementation. They prefer not to chase every new product innovation. Personal Investing Mistakes and Behavioral Lessons: The hosts share regrets including missing Bitcoin and buying expensive homes, using them to illustrate hindsight bias, the difficulty of counterfactual thinking, and how large financial decisions often dominate outcomes more than marginal portfolio tweaks.

Key Arguments: Lump-sum investing is superior most of the time; dollar-cost averaging mainly helps investors manage regret and anxiety, not expected returns. An advisor’s job is often to provide base rates and context, not predictions, which improves decision quality and reduces emotional mistakes. For Canadian investors, mutual funds can be tax-efficient relative to ETFs because the Capital Gains Refund Mechanism depends on redemptions, and mutual funds often have more taxable redemptions to offset. Dimensional’s Canadian mutual funds have had very small or no capital gains distributions in recent years, while comparable ETF asset-allocation products have distributed capital gains more frequently. Discount bonds can still offer after-tax advantages for taxable investors; those advantages do not appear to be fully priced away in the Canadian bond market. Buffer ETFs create the illusion of downside protection without reliable evidence of superior outcomes; simpler stock/cash combinations often do better. If an investor is so worried about a lump-sum drawdown that they prefer DCA, that may indicate the portfolio is too aggressive rather than a need for a more complex timing strategy. Technology may scale some advisory functions, but the hosts doubt AI or robo-tools can fully replace human financial planning because personal finance is more complex than transportation or simple automation tasks.

Data Points: Lump-sum investing success rate: about 65% - In the hosts’ 2020 comparison across six stock markets, lump-sum investing beat dollar-cost averaging in about 65% of sample periods. Estimated annualized cost of DCA: about 38 bps over 10 years - The paper estimates the opportunity cost of dollar-cost averaging relative to lump-sum investing. Worst-case lump-sum outcomes vs. DCA: DCA still trailed more than 50% of the time - Even in the worst 10% of lump-sum outcomes, dollar-cost averaging did not reliably win. Registered-account contribution question: January top-ups to TFSA, RRSP, RESP - A listener asked whether to invest contributions immediately or space them out over weeks/months. Canadian tax section for CGRM: Section 132.1 - Referenced as the Income Tax Act provision enabling the Capital Gains Refund Mechanism for funds in Canada. U.S. tax section for ETF in-kind treatment: Section 852(b)(6) - Cited as the U.S. Internal Revenue Code rule supporting ETF tax efficiency via in-kind redemptions. Example portfolio distribution history: Dimensional Global 60/40: no capital gains distributions since 2014; Vanguard 60/40 asset allocation ETF: distributions every year since inception - Used to illustrate structural tax differences between mutual fund and ETF wrappers in Canada. Vanguard 60/40 capital gains distributions: more than 40 bps of NAV in many years - Used as an example of taxable distributions from an ETF portfolio. Vanguard all-equity ETF distribution history: 30 bps in 2021, 80 bps in 2022, 10 bps in 2023, 20 bps in 2024 - Shown as evidence of recurring capital gains distributions in the ETF structure. Listener net worth example: less than US$300,000 - Used in the question about the need for behavioral/accountability support for smaller-net-worth investors. Bitcoin price mentioned in passing: about $146,000 - Used rhetorically in a discussion of regret and missed opportunities. Home-buying example: Toronto house bought in 2014, sold in 2017, roughly 4x gain - Used as a counterexample to typical investment mistakes and to illustrate housing as a major financial decision. Buffer funds paper title: Rebuffed: An Empirical Review of Buffer Funds - Cited as the key academic paper evaluating buffer strategies.

Pivotal Quotes: "Once you see it, you can't unsee it." — Cameron Passmore: Used to describe the appeal and adoption of the firm’s planning-plus-markets philosophy after people observe it from the inside. "The majority of buffer funds that they study have produced inferior risk-adjusted returns compared to their reference asset." — Ben Felix: Summarizing the AQR paper’s findings on buffer ETFs and structured strategies. "We provide base rates." — Ben Wilson: Describing the core value of an advisor: giving clients decision-relevant probabilities and context they otherwise lack.

Implications: Listeners are encouraged to favor simple, evidence-based implementation, invest contributions promptly when risk-appropriate, and use advisors or tools for behavior—not market timing. The episode reinforces skepticism toward complex products and product marketing.

From the Episode

See what we're doing, once you see it from the inside and really see how it's working and how well it's working and the impact it's having on clients, you can't unsee it. Once you see it, you can't unsee it. We've heard that a bunch of times. I'd add one thing actually on our philosophy, Cameron. You mentioned our mission, our model as being the combination of financial planning with the markets, work investment philosophy. I think that's true, and that's what we've been saying. I would add to that, though, that the finding and funding a good life piece, you can maybe lump that in with planning, but I think it's distinct. And it's such an important part of the way that we work with clients and part of our firm's DNA. I talked to one of our employees earlier today about how impactful that paper and those ideas, taking the principles of living a good life of wellness and happiness, and turning that into something that's actionable from a personal finance perspective, was super impactful to their own life. So I've just been thinking about that. I think it is part of our DNA. That's a very good point. Duly noted. Agreed. All right. Should we carry on to?

Cameron Passmore · at 4:34

And taking the care to give a fulsome answer on this relatively basic question, but it's an important one. I would summarize everything you just said, Ben: we provide base rates. Not everybody has base rates, and they're not always easy to establish. One of the other what-if scenarios we looked at was like, okay, what if markets just dropped? We just had a 20% or greater drop in the market. Now, does dollar cost averaging make sense? Because I think people will get that perception too. Okay, but yeah, with things being. Like they are right now. I think I should probably dollar cost average. It's the same thing. Lump sums are still better on average and most of the time. And then we also looked at investing a lump sum when U.S. stock valuations were in the 95th percentile of expensiveness. And again, lump sums continue to dominate. The irony of what you just said, things are going to drop, or they're as good as they could be right now. So there's bound to be a recession. I think I've heard a client say that literally every single year since I've been at PDF.

Ben Wilson · at 13:13
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About The Rational Reminder Podcast

A weekly reality check on sensible investing and financial decision-making, from three Canadians. Hosted by Benjamin Felix, Cameron Passmore, and Dan Bortolotti, Portfolio Managers at PWL Capital.

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