30-year bonds slide 64 basis points as whale block trades flood Treasury futures

UMBS 5.0 closed at 96.78, down 64 basis points from Monday's close, as over $20 billion in Treasury futures block trades — the largest single-day volume on record — drove yields higher. The 10-year Treasury ended at 4.673%, up 8.8 basis points. Analysts point to just one or two institutional players behind the move, not broad-based selling; other market participants held their positions through the session. Mortgage rates are now up 0.75% since the start of the trade war. Defensive float stance warranted — no clear catalyst to call a reversal.