A spike in oil prices could keep CPI inflation above 3%. In this environment, the Fed cannot cut rates to support a weakening economy, as doing so would spook bond traders, risk higher long-term rates, and make financial conditions even tighter, effectively taking them 'off the table.'

Investors' inflation expectations remain anchored due to recent disinflationary history and a strong belief in technology's deflationary power. This creates a market where the significant, non-zero risk of a new, higher inflation regime is not properly priced.

A sustained rise in oil prices presents a dual threat to investors. It can simultaneously increase inflation—hurting bond prices—and slow economic activity—hurting stock prices. This combination, known as stagflation, can cause both key asset classes to fall together.

It's the volatility and unpredictability within the supply chain environment—rather than the magnitude of a single shock—that can dramatically amplify the inflationary effects of other events, like energy price spikes. This suggests central banks need situation-specific responses.

The Federal Reserve can tolerate inflation running above its 2% target as long as long-term inflation expectations remain anchored. This is the critical variable that gives them policy flexibility. The market's belief in the Fed's long-term credibility is what matters most.

While the direct impact of tariffs may be temporary, the elongated process risks making consumers and businesses comfortable with higher inflation. Combined with questions about the Federal Reserve's political independence, this could unmoor expectations and make inflation persistent.

An oil supply shock initially appears hawkishly inflationary, prompting central banks to hold or raise rates. However, once prices cross a critical threshold (e.g., >$100/barrel), it triggers severe demand destruction and recession, forcing a rapid policy reversal towards aggressive rate cuts.

The knee-jerk reaction to a geopolitical shock is often a bond market rally (flight to safety). However, if the shock impacts supply (e.g., oil), the market can quickly reverse. It pivots from pricing geopolitical risk to pricing the risk of persistent inflation, forcing yields higher in anticipation of rate hikes.

The longevity of above-target inflation is a primary concern for the Fed because it can fundamentally alter consumer and business behavior. Historical models based on low-inflation periods become less reliable. Businesses report being surprised that consumers are still accepting price increases, suggesting pricing power and inflation expectations may be stickier than anticipated.