These types of vaults are marked with specific sign.
They use 99% of profit to buy underlying assets and redeposit it into the vault to increase value with time.
For understanding how it works you should know the mechanics of the Vault.
When you deposit into the Vault you get xToken - it is an interest-bearing token for this vault and a ticket for getting deposited assets back. xTETU is one of them but each Vault has an individual xToken (xNAME_OF_VAULT)
Each Vault has a Price Per Full Share (PPFS) - it is a ratio between underlying asset and xToken
When you deposit an asset you get xToken in this proportion.
For example, if you deposit 1000 USDC with PPFS 1.5 you will get ~666 xUSDC
If you withdraw your assets with 666 xUSDC and PPFS increased to 1.8 you will get ~1198 USDC
APR formula includes some period of work
We are getting two points of time
PPFSChange = endPPFS - startPPFS
Time = endTime - startTime
On the UI we are showing an average value of APRs for the last 7 days (with 1 day step)
Autocompounded vaults can have claimable xTETU rewards - they will be shown together
Vaults with underlying vaults
Some vaults uses other vaults as underlying.
Currently dxTETU uses xTETU as underlying. TetuSwap vaults does something similar with two vaults connected to a swap pair.
We are showing underlying vaults APR as additional income.
It is a dedicated calculation - the main Vault can have individual autocompound APR + rewards APR