NEW YORK: Wall Street stocks dipped early Monday as markets grappled with a US criminal investigation into the Federal Reserve that outgoing Chair Jerome Powell called politically motivated. Powell disclosed Sunday that the US central bank received grand jury subpoenas Friday related to his Senate testimony in June, which concerned in part a major renovation project of Federal Reserve office buildings. US stocks fell, while US Treasury bond yields and prices of gold and silver rose in a sign investors favored lower-risk trades. About 15 minutes into trading, the Dow Jones Industrial Average was down 0.5 percent at 49,271.82. READ MORE: Wall Street Week Ahead: Earnings start, inflation data pose tests for resilient US stocks The broad-based S&P 500 slipped 0.2 percent to 6,953.38, while the tech-rich Nasdaq Composite declined 0.1 percent to 23,642.65. The clash with Powell has exacerbated concerns about Fed independence, said Steve Sosnick of Interactive Brokers. “One of the things that Trump likes to do is see how far he can push the envelope,” Sosnick said. “If the market doesn’t react extraordinarily negatively to his moves against Fed independence, that will probably embolden him to keep trying.” “It appears that there’s a bit of a sell America trade going on today but I guess it could be worse.” This week’s calendar includes results from JPMorgan Chase and other large banks, as well as consumer price and retail sales data.