The evidence overwhelmingly supports the statement. Multiple high-authority financial news sources directly state that stock futures and indices reacted positively to the release of the December CPI data. The Yahoo Finance report is particularly strong evidence, as its URL slug explicitly says "futures-turn-higher-after-cpi-inflation-eases". Similarly, the market updates from Schwab ("Stocks Rebound on Cool CPI") and ADM Investor Services ("stock indexes were higher following the release of December's CPI") directly attribute a positive market move to the inflation report. The primary CNBC report also notes the S&P 500 turned positive on the day of the release. Sources that might initially seem contradictory do not directly refute the claim upon closer inspection. The BlackRock commentary discusses market performance over a full week and attributes it to a different catalyst (the jobs report), making it less relevant to the specific, immediate reaction to the CPI news. The Trading Economics summary mentions that stocks "fluctuated," which does not contradict an initial positive turn. The second CNBC article mentions a retreat for the day, but this describes the full day's trading and does not negate the possibility of an initial positive spike immediately following the 8:30 AM EST data release. Given the strong, direct, and consistent reporting from multiple credible sources specifically linking a positive market turn to the CPI release, the statement is assessed as likely true with high confidence.