August closed at the year's weakest levels: the 30-year fixed averaged 6.87%, the highest since June 2025, and the 10-year Treasury finished at 4.751%. The day ended better than it traded, though — bonds gave back most of the morning's losses into the close.

The damage was done early. UMBS 5.5 was off 0.19 by 9:33 AM ET and still down 0.16 at midday, then recovered through the afternoon to close at 99.02, down just 0.07 on the day. The 6.0 coupon finished at 101.13, down a single basis point — flat, for practical purposes. The 10-year traded as high as 4.761% mid-session before settling at 4.751%, up 3.9 bps.

The shape of the move says month-end, not a change of view. The 2-year closed unchanged at 4.343% while the 10-year and 30-year each added 3.9 bps. When the short end doesn't move and the long end does, on a day with nothing on the economic calendar, that's index rebalancing and duration adjustment — not the market repricing what it thinks the Fed will do. It's mechanical selling, and mechanical selling tends not to persist past the date that caused it.

For borrowers, 6.87% is a 14-month high, but the practical gap between today and late July is small — a few dollars a month on a typical loan, not a different deal. What actually matters is later this week: Jobless Claims Thursday and the August Jobs Report Friday. Those are the first real data since Warsh's Jackson Hole remarks reset expectations last week, and they'll determine whether this level holds or breaks.

— David Burson, NetRate Mortgage