Group 1 - The S&P 500 index experienced a three-day rally at the beginning of January, indicating potential upward momentum for U.S. stocks for the remainder of the month [1] - Historical data shows that January is the most active month for new capital inflows into the stock market, with an average monthly purchase ratio of stock mutual funds being the highest each January since 1984 [1] - The probability of the S&P 500 index rising in January is 62% since 1928, while the Nasdaq 100 index has a 70% probability of rising in January since 1985 [1] Group 2 - The S&P 500 index reached a historical high, and the Dow Jones Industrial Average closed above 49,000 for the first time, with the Dow gaining approximately 3% since the beginning of the month [2] - Market volatility remains low, with the Chicago Board Options Exchange Volatility Index (VIX) slightly above 14, having dropped below 14 before the Christmas holiday [2] - Retail investor enthusiasm is contributing to the expectation of billions of dollars in new capital inflows into the stock market this month, with corporate earnings growth momentum spreading beyond the "seven giants" [2]