Historical data is different from the data I downloaded before, what happened?

[0xngmi]

We change data (TVL, volume, fees...) retroactively to improve it's accuracy in the following cases:

• When listing a new protocol we fill in it's historical data
• If we discover that data for a protocol is wrong or the methodology we applied to it was wrong, we'll fix data for it retroactively so historical info is correct
• If a protocol had an update and our code for it became outdated because we weren't tracking the new update, after fixing the code we'll refill historical data to ensure historical data is accurate
• If we discover that a protocol has been incorrectly classified we'll re-classify it, this can impact chain TVL because if a protocol is marked as double-counted it will be excluded from chain charts by default

We list multiple protocols each day, and defi protocols are constantly changing, so updates to their metrics are also very common. Given that chain TVL is calculated as the sum of TVL of all protocols in the chain, this means that all these protocols being added or updated will lead to changes in historical chain TVL, so you can expect historical data to be changing regularly. These changes however are not usually large, since we usually already track all the main protocols of each chain, so new protocols being added typically have low TVL and thus the impact on total TVL is low.