Synthetic ETFs – When They Make Sense

Synthetic or physically replicating ETFs? Understand their differences, use cases and risks.

Overview

Physical ETFs hold all or a representative sample of index securities. Synthetic ETFs typically use swap agreements to obtain index returns.

What to consider

Synthetic replication can be useful for hard-to-access markets or indices, but it introduces counterparty and collateral considerations. Both structures can have tracking differences and fees.

Key takeaways

Read the prospectus, review swap counterparties, collateral rules, index exposure and historical tracking results. Neither method is universally superior.

How a swap-based ETF works

A synthetic ETF typically enters into a swap with a financial counterparty to obtain the performance of a specified index. The fund may hold a separate basket of securities as collateral or as a substitute portfolio. Its legal and operational arrangements are described in the prospectus.

Reasons for choosing synthetic replication

Some markets are difficult or expensive to access physically, and swap structures can sometimes reduce tracking costs. This benefit must be weighed against counterparty exposure, collateral quality, costs and the possibility of changes in tax or regulation.

Comparing alternatives

Physical and synthetic funds should be compared using realised tracking difference, fees, liquidity and the actual risk controls in place. Neither structure is automatically better for every index or every investor.

Questions to revisit

Before making a decision, ask what could go wrong, which assumptions must hold and how the position would affect your portfolio if markets move against you. Compare the potential benefits with the costs, complexity and liquidity constraints. A decision that fits your goals and time horizon is more useful than trying to predict every market movement.