Where to find last x hour/minute trading volume for a given coin Coinmarketcap shows trading volume for the last 24 hour. Where can I find trading volume for the last x hour/minute? Or How can I calculate it myself programmatically?
cryptocompare has the utility you need. 


Go to Coins at the top, find your coin
Analysis
Change the bar graph at the bottom to display by Hour
Use the interface to see the volume per second


If this is too unwieldy, cryptocompare does have an api and a useful npm package to play around with.