The May 2026 core update moved from rollout-in-progress to measurable impact over the Memorial Day weekend, with practitioners across multiple verticals and countries reporting traffic drops, surges, and volatility that tracking tools confirmed independently.
Our earlier coverage on May 22 reported the rollout start on May 21 at 11:43 am ET and noted the two-week deployment window. What has changed since: the update is no longer theoretical. Search Engine Roundtable’s Barry Schwartz, who has tracked core updates for years, wrote plainly that this one feels real, heavy, and like it got teeth. Multiple volatility trackers including Semrush Sensor, Mozcast, Advanced Web Rankings, SimilarWeb, Sistrix, and Wireboard’s aggregator all showed elevated signals running through Saturday and Sunday.
The winner-and-loser asymmetry is already pronounced, and the pattern is not clean. One practitioner reported a site in their niche gaining 100 percent traffic, despite content the community describes as inaccurate and a Reddit ban for misinformation. Another site lost 80 percent compared to pre-AI Overviews baselines. A third saw a 50 percent drop in a single day. These are not statistical outliers at the tail of a bell curve; they are characteristic of a core update still mid-deployment, where signal weighting is shifting faster than the SERP settles.
The Brazil Discover signal is the most geographically specific pattern to emerge so far. Smaller sites that had maintained visibility in Google Discover, even those with well-produced content, were removed during the weekend’s shifts. What replaced them in Brazilian Discover were news portals and sites with heavy backlink profiles. This is consistent with the update placing additional weight on authority signals in that context, though Google has not confirmed that reading.
International performance is outpacing US performance by a visible margin. One practitioner reported roughly 30 percent gains internationally against a smaller US uplift, and attributed the gap to the Memorial Day holiday distorting US signal reading. That explanation is plausible: search volume drops during US holidays, which can skew short-window percentage comparisons. SEO teams should be cautious about drawing strong conclusions from US-specific data collected between May 23 and May 26.
Glenn Gabe, who has documented core update impacts over multiple cycles, published his May 25 update noting that he had seen impact spreading across more verticals and countries since Saturday. His observation aligns with what community reporting from SEO Chatter shows: a wide variance in outcomes with no single vertical dominating either direction.
The rollout is not finished. Google’s stated window runs two full weeks from the May 21 announcement, which puts the expected completion around June 4. Treating current rankings as settled would be a mistake.
Two analytical points that this phase of the update makes concrete: First, a competitor gaining significant traffic right now may be gaining on a temporary ranking signal that gets revised before the update completes. One practitioner already described a surge followed by a drop through the floor within the same update window. Second, sites with strong pre-update baselines that are currently down should hold off on any structural or content changes until the rollout finishes; changes made mid-update will be difficult to evaluate because the ranking inputs are still shifting.
For practitioners running manual checks: the holiday weekend compressed US data, so a comparison of May 19 to 20 versus May 23 to 25 for US properties is more defensible than a seven-day average that includes May 23 to 26.
For teams whose competitors appear to have gained without clear quality justification, document what you see now: the URLs that gained, the queries they rank for, and the content characteristics. If those gains reverse after June 4, you have a useful comparison point. If they hold, you have a real diagnostic problem to work through.
Over the next 7 to 14 days, pull pre-update baseline data from Search Console before the 90-day window starts eroding your earliest comparison point, and flag any vertical where a competitor’s gain does not match a visible quality difference; that gap either closes when the update finishes or it identifies a ranking factor shift worth modeling.
Reported by Search Engine Roundtable (Barry Schwartz), published May 25 and updated through May 26, 2026, with additional field reporting from Glenn Gabe’s May 25 Core Update Notes.
