Why Stocks Fell Sept 9: Oil Spike, CPI Ahead

What Happened

The United States and Iran traded strikes on oil tankers and warships over the weekend, escalating the conflict that began in February. Iran vowed to target Middle East energy infrastructure in response to further US attacks. Brent crude rose to $97.31 per barrel on Monday, the highest since late July, while WTI climbed above $92. Commercial tankers are now being deliberately used as economic weapons, disrupting global supply chains.

Why It Matters

Higher oil prices threaten to reignite inflation just as the Fed debates whether to hike rates at its September 15-16 meeting. The conflict has already forced nations to burn through stockpiles to avoid deficits. If tensions near the Strait of Hormuz—which handles 20% of global oil flows—escalate further, analysts warn crude could top $100 per barrel and derail the Fed's progress on bringing inflation back to its 2% target.

Market Impact

What Happened

US stocks fell Tuesday as investors positioned ahead of Friday's August CPI report, due at 8:30 AM ET on September 11. The Dow shed 628 points, marking back-to-back losses following Monday's Labor Day holiday. Treasury yields surged, with the 10-year note hitting 4.82%—a level not seen since late 2023. Markets are now pricing in a higher chance of a Fed rate hike than a cut this year, a dramatic reversal from earlier in 2026.

Why It Matters

Friday's inflation data will be the Fed's last major input before its September 15-16 policy meeting. Strong August payrolls data already raised expectations for tighter policy, and if CPI comes in hot—especially with energy prices climbing—the Fed could hike rates for the first time since pausing in July. That would pressure corporate margins, mortgage rates, and consumer spending heading into the final quarter of 2026.

Market Impact

What Happened

Amgen shares plunged 10% on Tuesday after rival Novartis announced on September 4 that its experimental cholesterol drug pelacarsen failed to reduce heart attacks or strokes in a pivotal Phase III trial, despite successfully lowering lipoprotein(a) levels. The news rattled confidence in the entire Lp(a)-lowering drug class, including Amgen's own candidate olpasiran, which is in late-stage testing. BMO Capital downgraded Amgen to Market Perform, citing limited near-term upside and mounting loss-of-exclusivity headwinds on legacy products.

Why It Matters

Amgen is the fourth-largest stock in the Dow Jones Industrial Average, so its 10% drop weighed heavily on the index Tuesday. The trial failure raises doubts about whether lowering Lp(a)—a lipid linked to heart disease—actually translates to better patient outcomes, threatening billions in expected revenue for multiple drugmakers. Amgen's cholesterol franchise, including fast-growing Repatha, remains a key growth driver, but the setback could delay or derail its longer-term pipeline bets.

Market Impact

What Happened

August nonfarm payrolls grew by 162,000, crushing expectations for 53,000 and marking a sharp acceleration from prior months. The unemployment rate held steady at 4.1%. Combined with upward revisions to June and July data, the report suggests the labor market remains resilient despite elevated interest rates. Fed Chair Kevin Warsh and dissenting committee members have grown increasingly vocal about the need to raise rates to contain price pressures, especially with oil prices surging.

Why It Matters

At the start of 2026, markets were pricing in multiple rate cuts. Now, traders see a rate hike as more likely than a cut before year-end. The Fed's divided 9-3 vote in July—with three members pushing for a hike—signals that strong economic data and rising energy costs could tip the balance toward tightening at the September meeting. That would mark a major policy shift and challenge the equity rally that has powered stocks to near-record levels this year.

Market Impact