There's something oddly telling about today's market selloff. Out of the S&P 500, only 19 stocks managed to go up—that's brutally narrow.

Here's where it gets interesting: we've seen this exact scenario before. May 21 had a similar setup, and then SPX bled out for two more sessions after that. Go back a bit further to April 4—the day right before the major washout on April 7. Same pattern. So when breadth collapses this hard, the market's basically flashing a warning sign. It's not saying anything definitive, but historically these thin advance days have preceded some meaningful downside moves. Worth keeping in your mental model when the buying barely registers.