Nasdaq 100 tumbles 5.5%, worst day since April 2025

The Nasdaq 100 just got walloped. The tech-heavy index extended its losses to 5.5% on the day, according to the Kobeissi Letter, and is now on track to post its biggest single-day decline since April 2025.

The drop didn't stabilize as the session wore on — it deepened, with the index sliding further into the red rather than clawing any of it back. That kind of widening selloff signals sellers kept pressing rather than stepping aside.

There's another marker worth watching. The index is now sitting roughly 5% away from bear market territory, per the Kobeissi Letter. Bear market territory is the widely used label for a 20% fall from a recent peak.

So while 5.5% is already the worst day in about a year, the drop hasn't yet crossed into that deeper threshold. Another leg down of similar size would change that math quickly.