DeFi for people who use PayNow — why a pool is not a bank

Singapore – The old cryptonews.sg covered decentralised-exchange names the way a food blog covered new hawker stalls. KingSwap had its week; so did a procession of tickers whose liquidity lived for a fortnight and whose Telegram groups outlived the contracts. The news instinct was understandable. Someone had built a swap that did not look like a company. The instinct was also incomplete. A brand is a front end. The durable objects are a pool, a formula, a lending book with no banker, and a risk that does not care that you also use PayNow.

This briefing is for people whose other payment rail is a bank scheme. It is not a tutorial for farming a yield, not a review of any protocol, and not a recommendation to connect a wallet to anything. For the ledger underneath, start with blockchain without the jargon. For the habit of reading a project’s claims without the marketing, see evaluating a crypto project’s claims. Related pieces live in the explainers hub.

PayNow is a nickname for bank money

PayNow, sitting on FAST, lets you send Singapore dollars with a mobile number, an NRIC or a UEN. The Association of Banks in Singapore and the participating banks run the scheme. The thing that moves is a bank claim. If a transfer goes wrong, there is a bank, a scheme rulebook, and a path that does not require you to paste a transaction hash into a website you have never heard of.

That path is not perfect. Authorised-push-payment fraud exists. People send money to the wrong UEN. None of that turns PayNow into a token, and none of it turns a token pool into PayNow. The denomination is SGD. The issuer of the claim is a bank or a finance company in the scheme. The “address” is a proxy, not a public-chain destination.

When a founder says their app “feels like PayNow for DeFi”, ask what actually moves. If the answer is a token into a contract, the feeling is a user-interface choice.

An automated market maker is a jar with a formula

A traditional exchange is a book of bids and offers. Someone is willing to buy at a price; someone is willing to sell at another. An automated market maker (AMM) replaces that book, in the simple version, with a jar.

Users deposit two tokens into a smart contract — say a stablecoin and some other asset — and become liquidity providers. A formula, not a human market-maker, sets the price at which a third person can swap one token for the other. Every swap nudges the mix in the jar. The providers earn a share of the fees the formula charges. They also take the risk that the mix they get back is worth less, in Singapore-dollar terms, than the mix they put in. The industry name is impermanent loss. The “impermanent” is a hope. If you withdraw after the price has moved and stayed moved, the loss is as permanent as any other mark-to-market.

What you are actually holding

• You are not depositing with a bank. You are sending tokens to a program.
• The “price” is a curve, not a SGX print. Thin jars move a long way when someone swaps size.
• A fee APY advertised on a dashboard is a rear-view number. It is not a promise.
• The front end — the website with the friendly button — is not the contract. Anyone can build a lookalike page that talks to a different contract, or to the same contract with a different approval.

KingSwap-era coverage tended to stop at “a Singapore-flavoured DEX launched”. The educational remainder is the jar. If you cannot explain the jar, you are not using an exchange. You are signing a message you have not read.

A lending pool is not a savings account

The second object that inherits bank words is the lending pool. Users supply a token. Other users borrow it, usually by posting more value in some other token as collateral. If the collateral’s price falls far enough, the position is sold — liquidated — to protect the pool, or to protect the people the pool’s authors decided to protect.

The screen will say “supply APY” and “borrow APY”. The temptation, for anyone whose other reference point is a POSB statement, is to read those as interest on a deposit and interest on a loan from a bank. They are not.

A bank deposit is a claim on an institution that is not allowed to be casual about it. Eligible deposits have a compensation scheme. A lending pool is a set of balances inside a program, plus oracles that tell the program what collateral is worth, plus liquidation bots that do not work office hours, plus an admin key or a “governance” process that can change parameters. When the oracle is wrong, the pool can liquidate the wrong people or fail to liquidate the right ones. When the contract is wrong, the pool can empty.

Over-collateralisation is a design choice, not a cushion from MAS. It means borrowers post more than they take. It does not mean suppliers cannot lose the asset. Bad debt, frozen markets, a stablecoin that was not stable, a governance vote that changes the rules — those have all happened on protocols that still have websites.

A pool can look as fast as PayNow and still be the opposite object: no scheme, no deposit insurance, no recall, and a program that will do exactly what it was written to do, including the parts the author did not intend.

Smart-contract risk is ordinary engineering risk with irreversible money

“Smart contract” means a program stored on a chain that will run when someone pays to run it. The program can hold tokens. It will not exercise judgement. It will not notice that you are a person in Toa Payoh who thought they were clicking the official site.

The ordinary failures:

• Bugs. An edge case that a test suite missed. An integer that wraps. A re-entrancy the authors had read about and still shipped.
• Admin keys. A “decentralised” protocol whose upgrade path is a multisig in a founder’s drawer. Useful for fixing bugs. Also useful for changing the deal.
• Oracles. The contract believes a price feed. The feed lags, or is thin, or is pushed around. Liquidations follow the feed, not your sense of fairness.
• Front ends and approvals. You sign a permission that lets a contract move tokens later. A malicious or upgraded contract uses the permission. The chain records a valid message.
• Bridges. Tokens that “exist” on a second chain because a program on the first chain locked them. If the lock is broken, the copies are a costume.

None of this is an argument that every contract is doomed. It is an argument that “audited” is a historical statement about a report, not a warranty, and that “TVL” — tokens recorded as sitting in a program — is not a credit rating. Evaluating those claims is a separate briefing; the link is above. The local habit to drop is the sentence “it’s on-chain, so it’s safe”. On-chain means visible and rigid. It does not mean correct.

What MAS does and does not do with this vocabulary

The Monetary Authority of Singapore does not regulate “DeFi” as a single product, any more than it regulates “the internet”. It regulates activities.

A business that deals in digital payment tokens, facilitates their exchange, transfers them, or provides custodial wallet services to the Singapore public is in Payment Services Act territory, whether the matching happens in a company’s engine or is wrapped in a website that talks to a pool. A token that behaves like a share or a unit in a fund can be a capital-markets product under the Securities and Futures Act even if the only place you can buy it is a contract. Advice that a particular person should put a particular asset into a particular pool can be financial advice.

Using a public protocol from a personal wallet is a different sentence from operating a DPT service from a Shenton Way office. The DTSP regime that tightened in 2025 was aimed at firms using Singapore as a base for overseas token business, not at a reader who connected a wallet. The reader is still on their own for the loss. MAS has said, often, that digital payment tokens are highly risky and that a licence is not a socialisation of that risk. A protocol with no licence at all is not a loophole that creates insurance. It is a gap.

There is no MAS-run compensation scheme for tokens lost to a contract. There is no SDIC cover. There is no FAST recall. A licensed platform you used as an on-ramp may help with an internal mistake. Once the tokens have gone into a program you approved, the platform is a bystander with a hash.

How to hear a DeFi sentence in this city

A translation table, not a user’s guide:

• “Earn yield.” You are taking protocol, smart-contract, token and, often, lock-up risk in exchange for a variable distribution. Not a fixed deposit.
• “Decentralised.” Ask who holds the admin key, who wrote the front end, who can pause the contract, and who you would sue. If the answer is “the community”, ask for a name.
• “Audited.” Ask when, by whom, of which commit, and what was out of scope. Then remember that reports do not move tokens back.
• “Our AMM is just like an exchange.” An exchange in Singapore, if it serves the public in DPTs, is a licensed business with a complaints process. A jar is a jar.
• “Just like PayNow.” PayNow is bank money. This is a token into a program. Stop at the first word of the slogan.

People who want to go further will go further, with or without this page. The educational obligation is narrower. If your other reference point is a green tick from DBS or OCBC, you are not under-informed for lacking a yield strategy. You are a person whose payment system has a scheme. DeFi borrowed the speed and the words. It did not borrow the scheme. The old site was right to treat the launches as news. This desk will treat the jar, the pool and the missing insurance as the news that lasted.