The quick answer to the first question is no, there are not always candles for DARWINs since their inception. But let me explain:
- Candles are created based on quotes received for the DARWIN. Therefore, migrated DARWINs won’t have candles prior to the migration date.
- Over the history of Darwinex, the DARWINs evolved having different risks. And these DARWINs with different risk are considered as different products, with different product names. In these cases there might not be candles prior to 2017 for current product risk.
- If the DARWIN was created after 2017 without migration data, there should be candles since its inception.
In relation to the description for the period calculations, notice that the candles of D1 for Mondays start at the time of market aperture on Sunday night, so every week there 5 day candles as maximum. But … searching for candles of 1H or below, there will be candles on Sunday night too.
I hope it helps.