0VIX Docs

Exchange Rate

Each oToken's value increases over time as interest accumulates in the market. The exchange rate between a oToken and its underlying asset determines the conversion rate, which grows as interest is earned.
exchangeRate = (getCash() + totalBorrows() - totalReserves()) / totalSupply()
The underlying function returns an unsigned integer, scaled by 1 * 10^(18 - 8 + Underlying Token Decimals).
function exchangeRateCurrent() returns (uint)