How it works

The sUSDb Vault is where stablecoin holders deposit USDC to earn yield from Lighter's LLP.

Yield Source

All yield comes from Lighter Protocol's LLP, which earns fees from trading activity on Lighter's perpetual trading platform.

When you deposit USDC:

1

Funds Deployed

Funds are deployed to Lighter's LLP.

2

LLP Generates Returns (or Losses)

The LLP generates returns or may incur losses.

3

Returns Reflected

Returns (or losses) are reflected in the sUSDb exchange rate.

The sUSDb Exchange Rate

sUSDb is a yield-bearing token. Your quantity stays the same — value changes through the exchange rate.

Event	Exchange Rate	Your 1,000 sUSDb
Deposit	1.00	1,000 USDC
After yield	1.05	1,050 USDC

LLP Can Have Losses

LLP returns are not guaranteed. The pool can lose money.

Day Type	Result
Profitable	Exchange rate ↑ (after fees)
Loss	Exchange rate ↓ (no fees charged)

Daily Settlement

Settlement occurs daily at 15:00 UTC+8:

1

PnL Calculation

Calculate previous epoch's profit/loss.

2

Exchange Rate Adjustment

Adjust the sUSDb exchange rate based on the calculated PnL.

3

Value Sync

Ensure sUSDb supply value equals LLP position value.

4

Fee Distribution

If profitable, distribute fees to LIT stakers and protocol as specified.

Performance Fees

Fees are only charged on profitable days:

Fee	Rate	Recipient
Protocol Fee	0% at launch (may adjust with notice)	Brighter Treasury
LIT Pool Fee	0-80% dynamic	LIT Stakers

Profitable day:
├─ Protocol Fee → Brighter Treasury
├─ LIT Pool Fee → LIT Stakers
└─ Remaining → You (exchange rate ↑)

Loss day:
└─ No fees, loss reflected in exchange rate ↓

LIT Pool Fee Rate

The Pool Fee adjusts based on utilization:

Utilization	Pool Fee
0-80%	0% → 30%
80-90%	30% → 50%
90-100%	50% → 80%

Higher utilization = Higher Pool Fee = More goes to LIT stakers, less to you.

Your Effective Yield

Your net yield depends on utilization:

Utilization	You Keep (approx)
Low (50%)	~81% of LLP yield
Medium (80%)	~70% of LLP yield
High (95%)	~35% of LLP yield

Understanding APR

APR displayed is calculated using Exponential Moving Average (EMA) of the pool's returns in the previous year.

APR is an estimate. Actual returns vary with market conditions.