All such one-day market motion stories are "non-stories" then. That the market is primed for a correction is a widely held belief. Eventually there will be a "US stocks fall" story that meets your notability criteria, no?
Given that the prior for this is so high along with how many different beliefs there are about why the stock market changes, I'd say that there's a fairly low probability that any given news article's explanation is the real reason behind why it moved 1%.
Complex systems can be stable but close to collapse. Individually within we see stability and presume everything is fine while laughing at preppers. After a crash we can see all the signs that were there, and we retcon stories about crashes.
Complex systems seem to crash suddenly once a point of criticality is teetered over, where causes and effects that feed on each other driving the crash harder (positive feedback is not positive).
We retroactively create stories about dependencies (Archduke Franz Ferdinand).
Watching systems come back up after a shock is also weird (earthquake in my hometown Christchurch was a spectacular example of recovery).
Trying to diagnose how modern financial crises occurred is eye-opening.
Stocks are up ~9% over the last 6 months and are marginally off of all time highs.