Mortgage rates were very nearly unchanged today, although the average lender was just slightly higher. Investors reacted to news over the weekend that the US/China tariff deadline would be extended. While that doesn't have anything to do with mortgage rates, it set market forces in motion that created the modest, indirect effect.
The looming tariff deadline had been a source of uncertainty for markets. All other things being equal, uncertainty tends to promote some safe-haven buying in bonds and some weakness in stocks. When investors are buying more bonds, it helps push rates lower (or keep them from going higher). Of course, this uncertainty trade must be balanced against a variety of other considerations for investors. Moreover, the news in question wasn't a solution to the trade negotiations--just a delay. As such, it didn't have huge repercussions for markets.
Potentially more important will be congressional testimony tomorrow with Federal Reserve Chair Jerome Powell. The Fed's policies don't dictate the longer-term direction of rates, but they can definitely create short-to-medium-term volatility. With numerous Fed members out last week voicing opinions on key policy changes, Powell's testimony many well solidify the market's expectations heading into the next Fed meeting in just over 3 weeks. That could create some bigger movements for rates than we've seen recently