The Charts panel provides helpful markers to indicate exact times for a product 's price changes, based on fulfilment, New listings, Sales Rank and Amazon's listing. The different markers for each data source are:
FBA - transparent red triangle
FBM - transparent blue square
Buy Box - filled-in purple diamond
New - filled-in blue square
There is no Amazon marker as the yellow section is already filled in quite prominently on the chart.
For a more in-depth look at the Charts panel, check out this deep-dive video here to find out how this feature can enhance your sourcing strategy.