Where can I find market volume data with greater resolution than 24hr periods? I have scraper that pulls data from coinmarketcap for all coins for all historic periods (down to 15min intervals) however, the only volume info available is 24hr volume. Does anyone know if it's possible to get 15m/1hr volume data (historic) from coinmarketcap? Failing that, any reasonable approach for converting the 24hr data to 1hr/15m? It would only be a rough estimate, I know. I don't know why they don't provide hourly volume data as well.
You could do your own price comparison.

So if you scrape every 15 minutes. Store that 15 minute price data and create your own percentage based on the history of the data you collected.

If you have the data every 15 minutes you could even do the difference in 15 minutes intervals.

Example:
Price now is $1.00.
Our database says the price 1 hour ago was $1.15
Change of -13% over the past hour.

Again, store all the 15 minute scraping price data in your database and then use that data to make the percent based on whatever time frame you want.