DeFi on Sui: DeepBook, Gasless Stablecoins, and Bitcoin in DeFi with Hashi

How DeFi works on Sui: DeepBook's on-chain order book, gasless stablecoins, and Bitcoin access via Hashi

DeFi promised financial infrastructure that anyone could build on and no one could shut down. In practice, much of it runs on chains where fees and settlement times make small or fast trades impractical, and where the liquidity layer is a third-party contract bolted onto a base chain that was never designed for it. This guide covers how decentralized finance works on Sui: the liquidity layer, the cost and speed properties, the stablecoin design, and the institutional Bitcoin access that together make up the DeFi stack.

Before the protocols, the base layer has to deliver three things, because every DeFi application inherits them.

It needs speed that supports real markets. An order book or a liquidation engine that waits seconds for settlement cannot compete with the systems traders already use. Sui finalizes transactions in roughly 390 milliseconds, which is fast enough for market mechanics that depend on quick settlement.

It needs cost low enough that small transactions make sense. Average transaction cost on Sui stays under $0.02, and stablecoin transfers are gasless, making them cost nothing to send. When the fee to move money approaches or exceeds the amount being moved, a category of DeFi activity simply stops happening. Sui removes that floor.

And it needs an execution model that does not congest under load. Because Sui's object model lets independent transactions run in parallel, trading activity from different participants does not queue into a single lane. The chain scales horizontally: add hardware and throughput rises, with no congestion pricing that punishes users exactly when the market is busiest.

Most chains treat the liquidity layer as something protocols supply. Sui ships it natively. DeepBook is Sui's on-chain liquidity layer and financial infrastructure, and it has handled billions of dollars in trading volume.

Reviewer note: The original draft cited $19 billion in DeepBook volume. Per the comment, confirm the current cumulative figure with Amir before publishing; the number is softened to "billions" here until verified.

DeepBook exposes three composable primitives, which means other applications can build directly on top of them rather than reinventing market infrastructure.

The first is Spot: a fully on-chain central limit order book. Where an automated market maker derives price from a bonding curve and lets large trades suffer slippage, a central limit order book matches real bids and asks. On DeepBook this runs entirely on-chain with high throughput and without the slippage that AMMs impose. For traders and for protocols that need predictable execution, an on-chain order book is a meaningfully different tool than a liquidity pool.

The second is Margin: native leverage of up to 5x across DeepBook's pools, with liquidation logic embedded directly in the contract. Because the leverage and liquidation rules live in DeepBook itself rather than in a separate protocol, margin trading composes with the rest of the stack instead of fragmenting liquidity across venues.

The third is Predict: binary prediction markets with continuous strikes, native range bets, and embedded leverage. Under the hood these are options. That matters because it points at where DeepBook is going: a venue for on-chain options and structured products, including the vanilla calls and puts and exotic instruments that let treasuries and institutional traders write calls and hedge exposure entirely on-chain.

Two of Sui's design decisions change the economics of holding and moving value in DeFi.

The first is gasless stablecoin transfers. Moving any stablecoin on Sui is gasless, with no pre-purchased token to hold, whether the amount is a fraction of a cent or a large institutional sum. Sui supports gasless stablecoin transfers across multiple stablecoins at the protocol level, and it is live on mainnet. Stablecoins carry a large share of DeFi activity, so removing the cost of moving them takes friction out of every protocol that touches them.

The second is Sui Dollar, the network's native stablecoin, issued by Bridge (a Stripe company). Every stablecoin issuer holds reserves, and those reserves earn interest. Most issuers keep that interest. As Sui Dollar balances grow, Sui Dollar returns the interest earned on those reserves to the protocols and holders using it, rather than keeping it at the platform level. It also drives SUI token utility through a buy-and-burn mechanism. The design reflects a specific view of what on-chain money should do: be programmable, earn yield by default, and move without a per-transfer fee, so that participants with small balances are not priced out of using it.

Reviewer note: The original said Sui Dollar would "amplify DeFi yields," which a reviewer flagged as unclear. The paragraph above states the mechanism as reserve interest passed back to holders and protocols. Please confirm the exact distribution mechanism, and whether "amplify DeFi yields" was pointing at something more specific.

Transaction amounts can also be kept confidential: Sui is adding confidential transfers, which keep the amount of a transfer private on the public ledger while the sender and recipient stay visible. The feature is in beta on devnet. DeFi participants who do not want every position size exposed to public view can transact with confidential amounts while the system keeps the auditability it needs.

The largest pool of value in crypto, Bitcoin, has mostly sat outside DeFi because the bridges to bring it in came with custodial risk and tax friction. Hashi is Sui's answer: a decentralized protocol for Bitcoin in DeFi, being built to be institutional-grade.

Here is how it works. Bitcoin stays on the BTC network. Hashi uses the decentralized nature of Bitcoin and the speed of Sui to let BTC holders borrow from DeFi or earn yield, without a taxable event, a point supported by a legal opinion, and without custodial trust assumptions. The design includes an on-chain insurance fund denominated in BTC, and more than 20 institutional partners signed on, among them BitGo, Ledger, Cumberland, and FalconX. Hashi has not shipped yet, and a global testnet is scheduled for July 2026. When it ships, a holder would click a button, deploy BTC, and start earning yield or borrowing dollars.

For institutions, the combination of a legal opinion on the taxable-event question and the absence of custodial trust assumptions is what would turn Bitcoin in DeFi from a risk-committee problem into something an asset manager can actually use. That is why Hashi is a signal that institutional engagement on Sui is moving from experimentation toward foundation-laying.

A developer building a DeFi application on Sui is not assembling market infrastructure from scratch. The liquidity layer is already there in DeepBook, with an on-chain order book, native margin, and a path to options and structured products. Stablecoins move gaslessly, Sui Dollar passes yield back through the system, and transaction amounts can be kept confidential. Bitcoin can be brought in through Hashi once it ships, under institutional trust assumptions. Underneath all of it, the object model gives parallel execution and the Move language makes asset safety the default.

What sets the Sui stack apart from assembling the same pieces elsewhere is the integration. On Sui these pieces were built to compose from day one, rather than being stitched together from protocols and bridges that were designed separately and have to be trusted individually. For a builder, that means less time wiring together third-party liquidity and custody, and more time building the application itself.

Sui finalizes transactions in about 390 milliseconds, keeps average cost under $0.02, moves stablecoins gaslessly, and runs independent transactions in parallel so the chain scales rather than congesting. It also ships a native liquidity layer (DeepBook), a native stablecoin (Sui Dollar), and is building institutional Bitcoin access (Hashi).

DeepBook is Sui's native on-chain liquidity layer, with billions of dollars in trading volume. It offers three composable primitives: Spot (a fully on-chain central limit order book with no slippage), Margin (native leverage up to 5x with in-contract liquidation), and Predict (prediction markets that are options under the hood).

Moving any stablecoin on Sui is gasless across multiple stablecoins at any scale, live on mainnet. Sui Dollar, issued by Bridge (a Stripe company), is the native stablecoin and is designed to pass yield back to the ecosystem and drive SUI utility through a buy-and-burn mechanism.

Through Hashi, a decentralized protocol in development that will let Bitcoin holders earn yield or borrow against BTC while it stays on the BTC network, without a taxable event (per a legal opinion) and without custodial trust assumptions, backed by an on-chain BTC-denominated insurance fund and more than 20 institutional partners. A global testnet is scheduled for July 2026.

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