September opens with the war premium back.

The calendar turned, and with it the mood. August, for all the turbulence of its final fortnight, was a good month — the S&P up 2.6%, the Nasdaq nearly 4%, carried by the AI trade and, earlier, cooling inflation. But September inherits the problems, not the gains. The Gulf clash that flared over the weekend became a two-way exchange on Monday, the first in a month, and oil pushed back toward $90, restoring the war premium that had briefly faded. That matters doubly now, because firmer energy feeds the inflation worry a hawkish Chair Warsh underlined at Jackson Hole, just as the market enters the week that decides the 16 September rate call. History adds a note of caution — September is, on average, the weakest month for US stocks — but the real story will be written by the data: ISM and job openings today, and above all Friday’s payrolls.

• Stocks eased into September — the renewed US-Iran clash and firmer oil set a cautious tone on the first day.
• August was strong regardless — the indexes booked solid monthly gains despite the late-month turbulence.
• Energy led, the rest lagged — crude’s surge lifted energy while rate-sensitive corners stayed under pressure.

Equity figures are Monday 31 Aug’s close; monthly figures are for August; rates, FX and commodity levels are the latest available and approximate. Single names appear as news, not recommendations. Times GST.

The de-escalation that looked, a week ago, like it might finally take hold has given way to renewed conflict. On Monday the US and Iran traded fire for the first time in a month, following the weekend strike on Iranian rocket launchers said to be preparing to lay mines in the Strait of Hormuz. The relative calm that had let Gulf export flows recover toward two-thirds of pre-war levels, and Brent ease below $90, is over: crude surged back toward $90 as the clash unfolded. The progress of the prior week — the Iran-Oman revenue-sharing framework, the improving throughput — has not been erased, but it is once again hostage to the fighting, and the market is right to reprice the risk. For the Gulf, the episode underlines the central reality of this whole period: the oil price, and with it a meaningful slice of the global inflation and rate outlook, now turns on each turn of a conflict that has no clear off-ramp.

Vault Wealth’s house view: we held the energy and gold hedge through last week’s optimism precisely because a framework is not a settlement — and the weekend proved the point. We keep the hedge and stay balanced and liquid, and we are glad we did not chase the equity rebound. The set-up into Friday is uncomfortable on two fronts: a live oil premium and a hawkish Fed, converging on the jobs report. We do not add risk here. A contained clash and a soft payrolls print would finally open the door to re-engage; a wider escalation or a hot jobs number would keep us defensive and could warrant more protection. Discipline over prediction.