What not to do with ETFs: Marc Jocum on investing mistakes - Ep 5: Portfolio Construction Series

In this Australian Investors Podcast episode, Owen Rask sits down with Marc Jocum from Global X for episode five of the portfolio construction series, this time taking an inversion approach: instead of focusing on the perfect ETF portfolio, they unpack what not to do.

Marc explains why investors so often start in the wrong place by chasing trailing returns in growth ETFs or headline yield in income ETFs. He argues that the better starting point is always what sits under the hood: the earnings growth, the income source, the concentration, the index methodology and the actual role the ETF should play inside a broader portfolio.

The conversation also explores the practical mistakes investors and even sophisticated allocators keep making, including overlap, paying too much in fees, misunderstanding spreads and liquidity, ignoring tracking error, and mistaking a strong short-term narrative for a durable thematic opportunity. Marc also explains why thematic ETFs get scrutinised so heavily and how to think more clearly about public market depth, commercial adoption, government support and longevity before taking a view.

They finish by breaking down the few times it really can make sense to sell an ETF, including when your thesis changes, when a life event forces the decision, or when rebalancing is needed. If you want a sharper checklist for avoiding avoidable ETF mistakes, this episode is a practical one to keep handy.

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