These graphs show the 7-day trends in positive test results for each state. The data has been retrieved from the Covid Tracking Project.
The graphs compare the number of positive tests for the most recent 7-day period to the results for the preceding 7-day period. In other words, they compare the most recent days 1-7 to days 8-14. This is done daily. The smoothing period needs to be 7 days for reasons I explain here.