Measuring Halal ETF Liquidity: Bid Ask Spreads, NAV Premiums and What Halal Ninja Missed: A Sharia Analysis for Muslim Investors (2026)

Verdict: Measuring the liquidity of a halal ETF is permissible, necessary due diligence, and it comes down to two published numbers: the median bid ask spread and the premium or discount to net asset value. Halal Ninja's guide to the subject taught both metrics correctly, and it deserves credit for that. It also froze its data in May 2021, ignored the creation and redemption mechanism that actually generates ETF liquidity, and contains no Sharia analysis at all. Five years on, the data underneath its verdict no longer exists. This article updates the numbers and supplies the fiqh the original never attempted.

A Muslim investor can spend weeks confirming that an ETF passes the AAOIFI screens and then hand back years of expense ratio savings in a single badly executed trade. Execution cost is real money. As of late July 2026, the SP Funds S&P 500 Sharia Industry Exclusions ETF (SPUS) holds roughly $2.86 billion in assets, and the Wahed FTSE USA Shariah ETF (HLAL) holds about $925 million. Both are screened. Both fund pages publish the numbers that decide what you pay on the way in; neither leads with them. You need to know which numbers to read, and how.

Liquidity is the ease of entering and exiting a position without moving the price against yourself. For an ordinary share, liquidity lives on the exchange: market makers hold inventory, quote a price to buy (the bid) and a price to sell (the ask), and earn the difference for providing immediacy.

An ETF is different in a way that matters enormously and that retail guides usually skip. An ETF share is a claim on a basket of underlying stocks, so it has an observable intrinsic value, the net asset value (NAV). When the market price drifts away from NAV, authorised participants can create new ETF shares by delivering the basket, or redeem shares for the basket, and pocket the difference; the mechanics are disclosed in every ETF's prospectus, and the resulting premium or discount is published daily on fund pages such as SPUS's. That arbitrage pulls price back towards NAV. The practical consequence: an ETF's true liquidity is the liquidity of its underlying basket, not the volume on its own ticker. A halal ETF holding a screened subset of S&P 500 companies can trade thinly on screen and still be deeply liquid, because Apple and Microsoft shares are never hard to source. Screen volume is the most quoted and least meaningful liquidity number. This is the single biggest omission in Halal Ninja's treatment.

Two metrics, both published on every fund page, do the real work.

Median bid ask spread. The gap between bid and ask, expressed as a percentage of price, taken as a 30 day median. This is your round trip toll: you pay roughly half the spread entering and half exiting.

Premium or discount to NAV. How far the market price sits from the value of the basket. Buy at a persistent premium and you have paid more than the underlying stocks are worth; the arbitrage mechanism usually keeps this small for funds holding liquid US equities.

Source: SP Funds SPUS fund page, accessed 26 July 2026. HLAL reported net assets of $924.51 million and a 0.50 percent expense ratio on the same date (Yahoo Finance), against SPUS's 0.45 percent; HLAL's issuer page could not be reached to verify a current median spread, and a snapshot quote is not the same statistic, so we do not publish one. Note that AAOIFI publishes no liquidity threshold: these are prudence metrics, not compliance gates.

Halal Ninja's article compared the two funds in May 2021: HLAL at a 0.07 percent spread and 0.09 percent median premium, SPUS at 0.23 percent and 0.21 percent. On that data HLAL was the clear winner, and the article said so.

Candidly, the piece deserves both praise and criticism. The praise: it picked the right two metrics when most halal investing content ignored execution entirely, and its core instruction, always use limit orders pegged to NAV, is a genuinely good habit. The criticism is heavier. The data has sat untouched since May 2021, and the comparison built on it can no longer be relied on: SPUS publishes a 0.02 percent median spread today against the article's own 0.23 percent, and has grown to three times HLAL's size. The article never mentions creation and redemption, so it cannot explain why underlying liquidity matters more than volume. It cites no sources for a reader to verify. And for an article aimed at Muslim investors, it contains not a single verse, standard, or scholarly reference: no riba, gharar, or maysir analysis of the thing being traded. To be fair, its chosen scope was trading mechanics; but the mechanics have fiqh content, as the gharar discussion below shows. A liquidity guide that goes stale is more dangerous than an honest gap, because it hands the reader a confident answer whose evidence has expired. Our version, which you are reading, gives you the current numbers, the mechanism, and the fiqh, and shows you where to check the data yourself when this page ages in turn.

Nothing in the liquidity mechanics involves interest. The spread is a fee earned for a real service, immediacy and inventory risk, which is compensation for work and risk, not a return on a loan. The riba exposure in a halal ETF sits elsewhere: residual interest income inside portfolio companies, which is why AAOIFI Shari'ah Standard No. 21, Financial Paper (Shares and Bonds) (issued 2004; English edition 2015), caps impermissible income at 5 percent of total income and requires purification of that portion. Screening and purification are covered in our AAOIFI guide.

Here liquidity has genuine fiqh content. Gharar is excessive uncertainty in the object or price of a contract. An investor who sends a market order for a thinly traded ETF does not know the price they will receive: jahalah in the price, which is the uncertainty the prohibition targets, though at retail scale it is gharar yasir, the minor uncertainty fiqh tolerates without invalidating the sale. Buying at a rich premium to NAV is a different defect, ghabn, paying above fair value, and it becomes blameworthy when the premium is obscured rather than disclosed. Disclosure and price discipline cure both. Allah says in Surah Al-Mutaffifin, verses 1 to 3:

وَيْلٌ لِّلْمُطَفِّفِينَ الَّذِينَ إِذَا اكْتَالُوا عَلَى النَّاسِ يَسْتَوْفُونَ وَإِذَا كَالُوهُمْ أَو وَّزَنُوهُمْ يُخْسِرُونَ

"Woe to those who give less [than due], who, when they take a measure from people, take in full, but if they give by measure or by weight to them, they cause loss." (Saheeh International)

Fair measure is a Qur'anic demand. Checking the spread and the premium before trading is the modern form of weighing correctly, and a limit order set near NAV converts an uncertain execution price into a known one.

The metrics themselves are neutral; what you do with tight spreads is not. Cheap execution makes intraday churning painless, and a screened ETF flipped daily on price wiggles is speculation on price movement rather than investment in productive assets. The risk and diversification analysis covers why risk-bearing in real enterprise legitimises profit while pure price betting does not. Measure liquidity to reduce the cost of investing, not to subsidise trading.

None of the three scholars in scope has published a liquidity threshold, because execution cost is a worldly prudence question rather than a compliance gate. The live disagreements sit one level up, on the fund structures liquidity serves. Mufti Taqi Usmani's conditions for equity investment (An Introduction to Islamic Finance, 1998) require a permissible core business, purification of interest income, and that the company hold some illiquid real assets: under the Hanafi principles he applies, a share representing nothing but cash may only change hands at face value, so real assets are what allow shares to trade at market prices at all. Sheikh Joe Bradford serves as Shariah advisor to the Zoya screening app (joebradford.net, 2020), whose published methodology applies AAOIFI Standard 21 to listed equities by default (Zoya Help Center). Mufti Faraz Adam's methodology, published through Amanah Advisors, examines revenue streams line by line and is, on our reading, the most exacting of the three on ancillary income. An investor persuaded by Usmani's framework will hold a narrower ETF universe than one following the AAOIFI default; the liquidity arithmetic in this article applies identically to whichever universe survives the screen. Whether index funds and ETFs are halal in the first place is treated in full in a separate analysis.

Before buying any halal ETF, open the issuer's fund page and read three numbers: median 30 day bid ask spread, premium or discount to NAV, and assets under management. Compare them across the screened alternatives; the gap between 0.02 percent and 0.23 percent compounds if you rebalance a halal portfolio regularly. Use limit orders, ideally set with reference to the fund's published intraday indicative value rather than the previous day's NAV, and avoid trading right at the open and close, when spreads are typically at their widest. Verify the underlying holdings pass screening yourself with the stock screener, and if your portfolio spans digital assets, apply the same discipline through the crypto screener. How ETFs sit alongside sukuk, gold and property is mapped in the asset classes guide.

ETF liquidity reduces to two published numbers plus one mechanism. The median bid ask spread and the NAV premium tell you the cost; creation and redemption explains why underlying basket liquidity, not screen volume, sets that cost. Halal Ninja taught the two numbers correctly in 2021 and then let the article fossilise: its data is five years old, the evidence beneath its verdict has expired, it never mentions the mechanism, and it offers no Sharia analysis. Take its one durable lesson, the limit order habit, and get the rest here: current figures, the fiqh of fair measure and gharar, and screeners to verify compliance before you ever look at a spread. Measuring liquidity is not a substitute for screening; it is the discipline that stops a compliant investment from leaking money on execution.

This analysis is educational and is not a fatwa or financial advice. Fund figures change; verify them on the issuer pages before trading.

What is the best measure of ETF liquidity? The median 30 day bid ask spread, read together with the premium or discount to NAV. Both are published on the issuer's fund page. On-screen trading volume is a poor proxy because ETF shares can be created and redeemed against the underlying basket.

Is a low volume halal ETF unsafe to buy? Not necessarily. If the underlying holdings are liquid large cap stocks, authorised participants can supply shares on demand. Judge the basket, then the spread, not the ticker's volume.

What did Halal Ninja get wrong about ETF liquidity? The metrics were right; the maintenance was not. Its May 2021 data still shows SPUS at a 0.23 percent spread, while the fund's published median spread in July 2026 is 0.02 percent, so the article's HLAL versus SPUS verdict no longer holds. It also omits the creation and redemption mechanism and any fiqh analysis.

Should I use market orders or limit orders for halal ETFs? Limit orders. A market order on a thin ETF accepts an unknown price, which is avoidable uncertainty. Set the limit with reference to the fund's indicative value and let the order work.

Does a premium to NAV make an ETF haram? No. It makes it expensive. Paying above the basket's value is a cost and transparency problem, and persistent premiums deserve suspicion, but the compliance question is settled by the activity and financial screens, not by the premium.

Do bid ask spreads involve riba? No. The spread compensates market makers for immediacy and inventory risk, a fee for service and risk-bearing rather than a return on lending.

How often should I re-check liquidity data? Every time you trade, and at minimum annually for holdings you rebalance. The reversal between HLAL and SPUS since 2021 shows how quickly static comparisons rot.