New York: US stocks fell on the week for the first time in a month as accelerating inflation raises concern about the sustainability of the economic expansion. Treasury yields fell for a three consecutive week. Energy and material shares led the benchmark S&P 500 lower on Friday, four days after the benchmark U.S. equity index closed at another record high. Amazon.com continued it's retreat from all-time highs, helping to send the tech-heavy Nasdaq 100 lower. Small cap stocks were hit hard, with the Russell 2000 having its worst weekly decline since October. The 10-year Treasury note yield registered a third week of declines.