Why Kamino is the yield engine

A peg-stability module holds idle USDC. That USDC has to be available instantly for redemptions. It also should not sit still and earn nothing.

Resolving that tension is Kamino's job in the Nest stack, and the resolution is not obvious until you understand what atomic withdrawal actually requires.

What the PSM needs from a yield venue

The Peg Stability Module lets anyone swap USDC for nUSD, and nUSD for USDC, at a flat 1:1 rate. When idle USDC is available, the swap is instant and cheap. When it is not, redemptions route through the collateral liquidation process instead, which is slower and involves the broader market.

To keep redemptions fast in normal conditions, the PSM keeps a USDC reserve. That reserve earns yield by depositing into Kamino's USDC lending market. The critical requirement is that a withdrawal from Kamino can happen in the same transaction as a PSM redemption request, with no queuing, no cooldown, and no slippage from the principal amount.

Kamino supports this. Deposits into Kamino's main USDC market can be withdrawn atomically in any size up to the available liquidity, within a single Solana transaction. The withdrawal does not require a separate keeper step or a time delay.

How yield flows to snUSD holders

Kamino pays a variable lending rate on USDC deposits. That rate reflects demand from borrowers in Kamino's market and fluctuates with on-chain liquidity conditions. At reasonable utilization, the USDC lending rate contributes meaningfully to snUSD's realized APY.

The yield from Kamino is one of three streams that flow into snUSD. The others are stability fees paid by nUSD borrowers and liquidation penalties when they occur. All three are on-chain and verifiable. Kamino's contribution is the only one that varies continuously with external market conditions rather than being set by protocol governance.

Why Kamino specifically

Kamino is the largest USDC lending market on Solana by total value locked. That scale matters for two reasons. First, deeper markets mean higher utilization rates and, generally, better yields for depositors. Second, deeper markets mean larger redemptions can be processed without meaningfully affecting the Kamino utilization rate.

A PSM redemption that withdraws $2 million of USDC from a $10 million pool is disruptive. The same withdrawal from a $500 million pool is not. Nest's choice of Kamino is partly a bet that the largest lending market on Solana will remain large enough that PSM activity does not create meaningful feedback loops into Kamino's utilization or rates.

Audit history and smart contract risk

Kamino's contracts have been audited by multiple independent security firms and have processed billions in cumulative volume. That track record does not eliminate smart contract risk, but it is a meaningful input into the decision. A protocol that has operated at scale without material incidents is more predictable than one that has not.

Nest treats its Kamino exposure as a protocol risk to be disclosed and monitored rather than a solved problem. The Risk screen shows the current Kamino utilization rate and the PSM USDC balance at all times. If Kamino utilization approaches levels where withdrawal guarantees could theoretically be strained, protocol governance can vote to reduce the PSM deposit or move reserves to a different venue.

What this isn't

Kamino is not the only way to earn yield on USDC on Solana. There are other lending markets, automated market makers, and structured products that accept USDC. Nest chose Kamino because it is the only venue that combines the liquidity depth, the atomic withdrawal guarantee, and the audit history that the PSM requires at launch.

If a better venue emerges, the governance process can route PSM reserves there. The vault contract is not permanently coupled to Kamino. It is coupled to the requirement that any yield venue must support atomic withdrawal. That requirement will not change.