This is structurally different from an exchange savings product. There, the platform holds your USDC and the yield depends on the platform remaining solvent. Here the vault is a public smart contract, your position is yours, and if SpendTheBits disappeared tomorrow you could withdraw from the vault directly.
Yield is variable and comes from real borrowing demand, so rates move. A vault paying well this month is not promising to pay well next month, and no rate shown in the app is a commitment.
Deposit into a vault
- 1
Open the Earn tab.
- 2
Pick a vault and read its Yield Safety Score before the rate.
The score is 0–100 and reflects the venue's risk, not its return. The highest advertised rate is not usually the best risk-adjusted one.
- 3
Check which chain the vault is on against where your USDC actually sits.
If they differ, the app routes through a bridge first. It will show you that as part of the plan rather than doing it silently.
- 4
Enter an amount and review the plan.
- 5
Leave a spendable buffer outside the vault.
The app cautions you when a deposit would leave too little liquid to cover gas. Being fully deposited on a chain you cannot pay gas on is an avoidable annoyance.
- 6
Sign the deposit on your device.
Good to know
- When you spend and your liquid balance falls short, the app unwinds exactly the shortfall from the vault just-in-time. Your money keeps earning until the moment it actually leaves.
- Treasury Auto-Defense can exit a position to liquid USDC automatically if the vault's safety score breaches its threshold, and alerts you. Without an owner-signed session grant it degrades to alert-only — it can never do anything other than withdraw to you.
- Fees: a small service fee, under 1%, applies when you withdraw from a vault, plus a small share of the yield you earned — never your principal — collected only at withdrawal. If you earned nothing, there is nothing to pay. The exact live figures are always shown in the app before you sign, and in Settings → Fees.
Frequently asked
You do. The vault position belongs to an address your keys control. SpendTheBits prepares the transactions; your device signs them; the vault is a public contract on-chain.
No. Yield comes from variable on-chain borrowing demand and can fall to near zero. Smart-contract risk on the vault is real and is what the Yield Safety Score is trying to price.
Yes for the vaults offered here, which are liquid lending vaults rather than locked or staked positions. Withdrawal is an on-chain transaction you sign, so it costs network gas.
Get SpendTheBits
A fully non-custodial wallet for 13 chains, free on iOS and Android. Your keys never leave your phone.