Understanding ETFs
August 07, 2023
Various expenses make up the total cost of ownership of an exchange-traded fund (ETF), including its expense ratio and bid-ask spread. Here, we examine a third element of the total cost of ETF ownership—premiums and discounts, which occur when an ETF’s market price differs from the net asset value of its underlying securities.
We dispel some myths about ETF premiums and discounts, explain why they can occur, and suggest how investors can make informed decisions. We also look at how premiums and discounts differ by asset class.
The value of an ETF is determined in a number of ways, each of which can affect an investor’s experience. First, there’s the net asset value (NAV). As with mutual funds, NAV is the assessed value of all of an ETF’s underlying securities.1
In other words, a fund’s NAV is its fair value. But unlike with mutual funds, ETF investors don’t transact at NAV.2 Instead, ETF prices are determined by the market.
An ETF’s market price is the most important price for investors—the one at which they buy and sell shares in the secondary market. Since market prices are ruled by supply and demand, an ETF’s market price can diverge from its NAV.
If there’s heavy demand from buyers, the price of an ETF can increase above its NAV (a premium). Conversely, if there’s heavy sell-side pressure, the price can dip below the NAV (a discount).
The beauty of the ETF structure is the “creation-redemption” mechanism, which allows new ETF shares to be created to meet demand or redeemed to reduce supply as needed. Creations and redemptions help keep an ETF’s market price in line with its fair value and limits severe premiums and discounts. As long as the mechanism is running smoothly, ETF prices should stay near fair values.
The biggest risk related to ETF premiums and discounts is realized when an investor purchases an ETF when it’s trading at a substantial premium and then sells it at a substantial discount. This is why it’s important to focus on the volatility of a fund’s premium or discount.
Many investors focus on an ETF’s average premium, but the stability of premiums and discounts over time will have a much more significant impact.
The following charts help illustrate this point:
Source: Morningstar, based on data from July 2018 through November 2019.
ETF A has an average premium of 18 basis points (0.18 percentage point), and ETF B has an average premium of 0 basis points. An investor looking at those averages might assume ETF B is a better product.
This would be incorrect.
Although ETF A does have a larger average premium, the premium is more stable, which reduces the investor’s risk and potential costs. If investors buy and sell at a stable premium, the cost is likely to be predictable and relatively modest. As the graph illustrates, an investor might buy ETF A at a premium of 22 basis points and sell at a premium of 18 basis points, incurring only 4 basis points of round-trip transactions costs. While it may seem a disadvantage to buy an ETF at a premium of 22 basis points, selling at a similar premium can offset this initial cost.
Conversely, ETF B has a smaller but more volatile premium, which exposes investors to the possibility of buying at a significant premium and selling at a significant discount. An investor who purchased at a premium of 64 basis points and sold at a discount of 61 basis points would incur 125 basis points (1.25 percentage points) of round-trip transaction costs. Selling at a steep discount only adds to the initial transaction cost.
Again, a larger but stable premium is often preferable to a lesser, volatile one. The standard deviation of historical premiums is arguably a clearer way to estimate transaction costs than the average premium.
It’s also worth noting that any ETF premium or discount published at the end of a trading day generally represents only the closing snapshot, comparing the ETF’s NAV to its closing price on its primary exchange. A premium or discount at the close may not accurately depict where the ETF traded relative to its NAV during the trading day.
Domestic equity ETFs generally trade in line with their NAVs. Premiums and discounts are typically slight for a variety of reasons, including the lower cost of buying and selling the underlying domestic equities, the relative ease of pricing underlying stocks and ETFs simultaneously, and the lower fixed fees incurred.
In other words, pricing domestic ETFs is relatively straightforward and can frequently be achieved without too much deviation from NAV.
International ETFs may have more pronounced premiums and discounts. It’s more challenging to determine the fair value of the underlying constituents, partly because the markets where they’re listed may not be open during hours when U.S.-listed ETFs are trading.
Other costs may include larger fixed fees, higher commissions, stamp taxes and associated fees, foreign exchange hedging costs, and the imprecise nature of fair value factors. This makes the process to create or redeem international ETFs less precise, which translates to larger premiums and discounts.
Fixed Income ETFs usually trade at inherent premiums. Their NAVs are based on the bid prices of all their underlying securities, or the prices at which the funds could sell all of their holdings.
A fixed income ETF’s market price will typically be near the midpoint of all the underlying bonds in the ETF’s basket. This represents what it would cost market makers to buy the underlying bonds to create new ETF shares, though sometimes an ETF can trade up toward the cost to create new shares.
Premiums and discounts are important components of the total cost of ETF ownership, and they vary by asset class. Their stability can be considerably more meaningful than their size. A larger, but stable, premium is often preferable to a lesser, volatile one.
While the existence of premiums and discounts should not lead investors to avoid ETFs, extremely volatile premiums and discounts can erode longer-term returns significantly. Investors can steer clear of relatively elevated ETF premiums and discounts by avoiding trading on days when markets are roiled. In any case, they should understand good ETF trading practices.
1 Certain funds may apply a fair value pricing methodology that will set NAV at different levels than the underlying securities’ official closing value.
2 ETF investors can make NAV trades; however, these trades typically need to be placed by a high-touch trade desk and are often executed with a markup or markdown to the stated NAV depending on the asset class and trade direction.
All investing is subject to risk, including the possible loss of the money you invest.
Bond funds are subject to the risk that an issuer will fail to make payments on time, and that bond prices will decline because of rising interest rates or negative perceptions of an issuer's ability to make payments.
Investments in stocks or bonds issued by non-U.S. companies are subject to risks including country/regional risk and currency risk. These risks are especially high in emerging markets.
Contributors
David Sharp
Patrick Hooper
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