Direct Answer
The ETF Premium/Discount Calculator computes the dollar and percentage difference between an ETF's current market price and its net asset value (NAV) using values you supply. It optionally calculates the bid-ask spread in basis points and the mark-to-NAV difference for a given position size. No live data is fetched.
ETF Premium/Discount Calculator
Calculator
What this calculator computes
Enter the market price and NAV per share, and the calculator returns:
- Dollar difference: market price minus NAV. Positive = premium; negative = discount.
- Premium/discount percentage: (market price - NAV) / NAV * 100. The SEC uses this formula in its ETF disclosure guidance.
With bid and ask prices entered, it also computes:
- Dollar spread: ask minus bid.
- Midpoint: (bid + ask) / 2.
- Spread percentage: dollar spread / midpoint * 100.
- Spread in basis points: spread percentage * 100.
With a share count entered, it computes:
- Market value: shares * market price.
- NAV equivalent: shares * NAV.
- Mark-to-NAV difference: market value minus NAV equivalent.
What is an ETF premium?
An ETF trades at a premium when its market price on the exchange is higher than its net asset value. NAV is the per-share value of the fund's underlying holdings. A premium means buyers are paying more than the value of the assets the ETF holds. Premiums are most common during periods of high demand for the ETF, in thinly traded funds, or when the underlying market is closed but the ETF is still trading.
What is an ETF discount?
An ETF trades at a discount when its market price is below its NAV. Authorized participants can generally arbitrage discounts away by buying ETF shares and redeeming them for the underlying basket, which is why large persistent discounts are rare in liquid ETFs. Discounts tend to widen during market stress or when the underlying holdings are illiquid and hard to price accurately.
Is a discount always good?
Not necessarily. A discount can signal that the ETF's stated NAV overstates the realisable value of the underlying holdings, particularly in markets where those holdings are hard to trade. Bond ETFs during credit crises have shown persistent discounts precisely because the underlying bonds were illiquid and their quoted prices were stale. A discount in a liquid, transparent ETF is generally an opportunity; a discount in an opaque or illiquid fund may reflect a real valuation problem rather than a buying opportunity.
Is premium/discount the same as bid-ask spread?
No. Premium or discount measures the gap between the ETF's market price and its NAV. Bid-ask spread measures the gap between the highest buyer price and lowest seller price on the exchange right now. Both are relevant trading costs, but they are independent. An ETF can trade at parity to NAV with a wide spread, or at a significant premium with a tight spread.
Is NAV calculated continuously?
Official end-of-day NAV is calculated once per trading day using closing prices for each holding. Some fund companies publish an indicative NAV (iNAV) throughout the day, but that is an estimate based on last-trade prices of the underlying securities and is not an official figure. Its accuracy depends on how liquid and continuously quoted those holdings are. For thinly traded or international holdings, the iNAV may lag materially.
Why not automatically fetch an ETF ticker?
Real-time market price and NAV data requires a licensed data feed. Using a live feed would add latency, API costs, and a dependency on a third-party service. More importantly, the relationship between market price and NAV is simple arithmetic once you have the two numbers: entering them directly makes the formula transparent and keeps the tool working reliably. For real-time data, check your brokerage platform or the ETF issuer's website directly.