economics Paradigm Challenge

The stock market doesn't fully react to global oil shocks until five whole days after they happen.

March 24, 2026

Original Paper

Oil shocks and real yield curves: Evidence from Brazilian inflation-linked bonds during the 2026 Iran crisis

Felipe Tavares

SSRN · 6460807

The Takeaway

Contrary to the 'efficient market' theory that information is processed instantly, this study of Brazilian bonds found an 'echo effect' where the biggest volatility spike happens a week later. It reveals that it takes professional traders an entire week of lag time to calculate the secondary inflation effects of a geopolitical crisis.

From the abstract

This paper investigates the high-frequency transmission of the early 2026 Iran geopolitical shock to the Brazilian real yield curve. Using a daily Vector Autoregression, VAR(5), framework , we quantify the magnitude and persistence of the oil supply shock across inflation-linked government bonds (NTN-Bs). We document a non-linear maturity pattern where the short end of the curve remains insulated by domestic liquidity factors , while the intermediate segment—specifically the 2030 maturity—acts a