This round of US-Iran negotiations is more like pressing the pause button rather than a true easing of the situation.

After 40 days of conflict, the first time they face each other face-to-face, it seems to release goodwill, but Iran's proposed terms remain tough, and the essence of the negotiations is still a trade of interests. More importantly, the risk in the Strait of Hormuz has not been lifted, and the mine-warfare issue keeps the situation tense on a real-world level.
This 15-day window is actually a "watching period" for the market. If an agreement is reached, risk assets will recover; if it collapses, oil prices and sentiment could reverse at any time.
The current market is not a trend but is being driven by news pricing.