The chances of an agreement are extremely slim, according to a US source involved in negotiations with Iran, via Al Arabiya

Sourced pessimism from a named-side participant in Iran negotiations fits a familiar pattern in this file: negotiating parties have historically used unattributed briefings to pressure counterparts, and a low-probability read at this stage of talks has on previous occasions preceded both breakdowns and, in other instances, last-minute compromises. The transmission channel for crude is the prospect of sanctioned barrels staying off the market: a failed agreement keeps existing export constraints in place, while any eventual deal path would raise the question of how quickly Iranian supply and floating storage could return, which has historically been faster than consensus assumes. The distinction worth drawing is between a procedural setback, where talks continue and the status quo holds, and a formal collapse, which revives the tail risks around enforcement, regional escalation, and shipping insurance in the Gulf. Premia in these episodes have tended to build in the front of the curve and in call skew rather than in outright length, and to fade when talks resume. The follow-ons are whether the other side contradicts the briefing, whether a next round is scheduled, and any movement in enforcement rhetoric toward Iranian flows.