"If oil stays near $80, there's no way the Fed raises rates in September."

Jeremy Siegel, Wharton School Professor of Finance and WisdomTree's Chief Economist, on CNBC

Siegel's call follows this week's better than expected CPI and PPI data. Goldman Sachs has lowered its estimate for the upcoming PCE deflator, the Fed's preferred inflation gauge, noting the modest uptick still expected is mostly due to rising portfolio management fees, not underlying inflation.