Spark Opens USDT Savings Vault to OKX Users

DeFi capital allocation platform Spark is extending its USDT savings vault to customers of centralized exchange OKX. The partnership allows OKX users to earn on‑chain yield on stablecoin balances directly from the OKX app, without needing to create a separate wallet or bridge assets themselves.

How the product works

OKX aggregates user deposits and routes them to Spark’s USDT Savings vault on X Layer, OKX’s Ethereum Layer‑2 solution. Deposits are pooled in a single vault contract that is also accessible to any X Layer participant. The vault offers a 3.5% annual yield, matching the rate set for Spark’s Ethereum USDT vault.

Vault capacity and liquidity buffer

Governance has set a supply cap of 750 million USDT for the X Layer vault and a maximum yield of 6%. Spark targets a liquidity buffer equal to the greater of 10% of total deposits or $1 million, capped at $10 million. Withdrawals are serviced instantly from this buffer, while excess funds are bridged back to Ethereum for deployment.

Deposit asset and capital deployment

Deposits on X Layer use USDT0, the LayerZero‑issued omnichain version of Tether’s stablecoin. Spark’s Liquidity Layer moves pooled capital across approved venues such as SparkLend, Morpho vaults, and real‑world asset strategies. For each USDT deposited, Spark borrows an equivalent amount of USDS, providing a 1:1 USDS backing for the vault.

Risk considerations

Spark’s risk council flagged X Layer’s limited decentralisation, noting that the chain’s security relies heavily on its operator, which can upgrade the network instantly. To mitigate exposure, Spark capped outbound transaction size at $5 million and limited the maximum yield to 6%. The council also required a 100% capital‑requirement ratio for the X Layer buffer until further review.

Geographic availability

The service will be offered to eligible OKX users worldwide, excluding the European Economic Area and other jurisdictions where OKX imposes restrictions.

Broader context

Spark currently manages about $6.47 billion in total value locked across multiple chains, with its SPK token trading around $0.019. The partnership with OKX is the latest integration, and both parties indicated that additional collaborations are under consideration.