In reply to katejoanbohl.

Yes, definately due to WordPress's security updates, because that explains why Drupal (http://www.alexa.com/siteinfo/drupal.org) and Joomla! (http://www.alexa.com/siteinfo/joomla.org) among have identical declines.

There's nothing to this, Alexa simply changed their ranking algorithims.

Also trying to figure out how much traffic a site has based on Alexa is ridiculous. You'd the same quality of an estimate if you asked a tree: https://syedbalkhi.com/alexa-is-bullshit-please-stop-using-it-as-a-traffic-comparison-tool/