Global oil prices tumbled on Tuesday, with Brent crude slipping below the $80-per-barrel mark for the first time since March, as investors reacted positively to signs of a breakthrough in negotiations between the United States and Iran and the anticipated reopening of the Strait of Hormuz.

Brent crude, the international benchmark, fell to around $80 per barrel during trading, while US West Texas Intermediate (WTI) crude dropped to $77.

The decline marked the latest phase of a sharp reversal in energy markets following months of heightened geopolitical tensions that had pushed oil prices above $100 per barrel earlier this year.

The sell-off comes amid growing optimism that a peace agreement between Washington and Tehran could restore stability to one of the world’s most critical energy corridors.

The Strait of Hormuz, which handles roughly one-fifth of global oil shipments, has been at the center of market concerns throughout the year after disruptions to maritime traffic threatened global energy supplies.