Riba in Plain Language, and Where It Hides in Crypto

Riba is the prohibition Muslims know best and recognise least. Everybody can tell you interest is haram. Far fewer can look at a screen offering 8% on idle USDC, or a token whose price is supported by buybacks funded from funding rates, and name what is happening.

This is a reference piece. What riba is, the two kinds, the nine places crypto puts it, and the things that look like it and are not.

The definition, stripped down

Riba is a stipulated increase received for the passage of time on a loan of fungible value, or an unequal exchange of like for like.

Two clauses, because there are two kinds, and almost all modern discussion only knows the first.

Riba al-qard, also called riba al-nasi'ah. You lend 100 and receive 110. The extra 10 is not payment for a service, for risk borne, or for effort expended. It is payment for time. This is the one everybody means when they say interest.

Riba al-fadl. Exchanging a quantity of a fungible commodity for an unequal quantity of the same commodity, or with delayed delivery. The hadith on the six commodities established that like must exchange for like in equal measure, hand to hand. This is the clause that governs currency exchange, sarf, and it is why simultaneous delivery matters.

The severity of the prohibition is not in question. It is the transaction the Qur'an singles out with a declaration of war in Surah al-Baqarah, which is language reserved for very little else. That is why the tradition treats it as a bright line rather than a matter to be optimised around.

Where it hides in crypto

Nine places, ordered roughly by how many Muslims are currently caught by each.

1. Exchange Earn, Savings and Flexible products. You deposit, the platform lends or deploys, you receive a stated annual rate. This is the plain case and it is where most Muslims with otherwise clean holdings pick up impure income. Some platforms sweep idle balances in by default, which means you can be earning it without having chosen to.

2. Lending protocols. Aave is a money market built entirely around interest-bearing lending, and the token's governance utility and Safety Module yield both derive from it. The absence of a bank changed nothing. The contract is money now for more money later, and a smart contract enforces it more reliably than a bank ever did.

3. Funding rates on perpetual futures. Perpetuals never expire, so the protocol charges periodic payments between longs and shorts to hold the contract near spot. Strip the terminology: a recurring rate paid for continued use of borrowed exposure. That is riba with maysir stacked on top from the leverage. It is what fails Hyperliquid and Aster.

4. Tokenized Treasuries and money market funds. Circle USYC holds Treasury bills and reverse repos, and the holder's token value rises automatically as the interest accrues. You are not adjacent to the riba, you are receiving it. Ondo tokenizes conventional bank deposits and interest-bearing government debt. Watch for the phrases real-world assets, RWA, on-chain Treasuries and tokenized yield. All of them mean interest with better graphics.

5. Stability fees on collateralised debt. Dai and USDS mint their dollar by charging fees on crypto-backed loans and earning interest on tokenized real-world assets, with over 33% of revenue from non-compliant sources. Decentralisation is an architecture, not a Shariah property.

6. Synthetic pegs built on derivatives. Ethena USDe maintains its peg by delta-hedging with short perpetual futures, so funding rates are the stability mechanism itself rather than a side business. When funding turns negative the reserve rotates into Treasury-yielding assets. Both legs are riba.

7. Preferred stock wrappers. Strategy PP Variable xStock tracks a variable-rate perpetual preferred instrument whose economic function is to pay a predetermined return. The operating company is clean. The instrument is not, and there is a full piece on that distinction.

8. Idle balance sweeps in trading bots. Many bot frameworks park uninvested capital in a yield venue between trades, because idle capital looks wasteful. That default setting generates interest quietly and continuously. Check it if you run any kind of bot.

9. Issuer-side reserve interest. Tether earns billions from Treasury bills and secured loans. Circle's revenue model runs on Treasuries and repo agreements. None of it reaches you, which is why holding USDT or USDC requires no purification and is not disqualified on riba grounds. It is worth knowing anyway, because your decision to hold rather than own is what funds it.

What is not riba

Getting this half right matters as much, because over-broad prohibition drives Muslims out of permissible commerce and into either paralysis or resentment.

Trading fees on an automated market maker. Uniswap collects a fee from traders for the use of a liquidity pool. Nobody lends anything and nobody is charged for time. That is ujrah, a service charge for a service rendered, and it is why an AMM can pass while a lending protocol cannot.

Proof-of-stake validation rewards, generally. A validator runs infrastructure, commits capital at risk of slashing, and secures a network. That reads as compensation for work or as a cooperative venture return. The open question is not whether staking is riba, it is whether inflationary emissions rather than real fee revenue count as earned, which is what puts Cosmos Hub at Doubtful.

Capital gains on a real asset. Buying Bitcoin at one price and selling higher is trade. Price uncertainty is ordinary commercial risk, which Islam permits and every merchant in history has carried. Nobody paid you for time.

Profit-and-loss sharing. Mudarabah and musharakah are the permissible alternatives to a loan, and the defining condition is that the capital provider genuinely bears loss. A structure promising a fixed return regardless of outcome is a loan wearing a partnership's clothes.

Miner and transaction fee revenue. Users pay for computation performed. Service for payment.

The 5% question

Most large businesses earn a little interest on their cash, which means an absolute standard would prohibit nearly all equity.

AAOIFI's screening standard tolerates non-compliant income below 5% of revenue, on condition that the holder purifies the corresponding share. Above 5%, the asset fails and purification is not a remedy. Our methodology applies that threshold alongside limits of 30% on interest-bearing debt and 30% on cash and interest-bearing securities.

In practice the numbers are usually not close. Tesla's tokenized share needs about 1.5% purification. Hyperliquid measures over 33% non-compliant revenue, six times the threshold. Borderline cases are rarer than people expect, and the mechanics of purifying are straightforward once you know the rate.

The test to carry

One question resolves most of it.

Is anybody being paid for the passage of time?

APY, APR, funding rate, stability fee, savings rate, yield, coupon. If value accrues to someone because a period elapsed rather than because a service was performed or a risk was borne, you have found it, whatever the interface calls it.

The second question, which catches the cases the first one misses: does the token's value get funded by anything in the list above? A clean token supported by buybacks from perpetuals revenue is not clean, and that is the specific reasoning behind our Hyperliquid verdict.

The rest of the framework, including the gharar and maysir tests that sit alongside this one, is on the methodology page.