 Investors waited all week for the Commerce Department to deliver its latest report card on inflation. When the news came Friday morning, it was generally encouraging. Prices in May were up 2.6% over the last year, a smaller annual increase than the month before. Stripping out volatile food and energy prices, so-called core inflation was the lowest it's been in more than three years. Investors are hoping that slowdown in price hikes will clear the way for the Federal Reserve to start cutting interest rates, perhaps in September.