Week 37: Oil Hits $100, CPI Seals the Deal: September Hike Now Near-Certain

Weekly Summary

Week 37 (8–11 September) was a shortened four-day week due to Labor Day on Monday, but it delivered more macro intensity than most full weeks. US-Iran hostilities escalated significantly mid-week, sending Brent crude to a peak of almost $110 per barrel and WTI through the $100 threshold for the first time in years. Then came Thursday's August CPI report — a reading that, while broadly in line with annual expectations, contained a hotter-than-expected monthly core figure that effectively sealed the case for a September rate hike. Markets fell for four consecutive sessions before Friday brought some relief, as oil prices pulled back sharply on reports of emerging Gulf diplomatic talks.

The S&P 500 lost 0.80% on the week, closing Friday at 7,656.98. The Nasdaq fell 0.70% and the Dow shed 426 points (-0.80%). Despite the weekly loss, Friday's recovery was meaningful: the S&P 500 gained 0.86%, the Dow added 509 points and the Nasdaq rose 0.96%, snapping a four-session losing streak as oil retreated and technology stocks — particularly AI infrastructure names — led a broad-based bounce.

For the Rivativ model portfolios, the week was challenging for the three theta-positive strategies, all of which absorbed mark-to-market pressure from the equity sell-off and the spike in oil-driven uncertainty. The Predictive Gamma Strategy, however, delivered a strong positive result in the down week. Combined weekly result: -$2,290.77 (-0.55%), versus SPX -0.80%: outperforming a falling market by 25 basis points. September month-to-date: combined -0.30% versus SPX -0.38%.