In the past week, the US stock market, which has a high P / E ratio, has stood still at a time when the US stimulus bill negotiations have stalled, US bond yields have risen and inflation has soared. To explain all this, some investors attributed the new outbreak data. < / P > < p > more and more evidence shows that the peak of virus outbreak in sunshine zone states of the United States has passed. The number of new cases per day, the positive rate and the number of inpatients seem to be improving. At the same time, real-time economic data also showed that the U.S. economy is recovering slowly and steadily, which has calmed investors’ nervousness, and the S & P 500 index has reached new highs several times. < / P > < p > “we’ve seen some really positive trends,” says Ryan Detrick, senior market strategist at LPL financial. “It’s all good news, partly explaining why stocks are at all-time highs.”. < / P > < p > to be sure, it is a difficult task to determine causality in any market. Any single event (including the improvement of the new cap data) as the reason for the rise of the stock market will increase the risk of data snooping, that is, applying the facts to the preset context. However, the new coronavirus has always been the theme of the stock market in 2020, when the health crisis led to the fastest bear market in history. Today, fund managers surveyed by Bank of America have the highest bullish share of the stock market since February, and they expect the new crown vaccine to be available in the first quarter of 2021. < / P > < p > investors saw the improvement of the new epidemic situation data. According to Tom Lee of fundstrat global advisors, the number of new cases in a single day in the United States has dropped dramatically, with new cases far below the peak in Florida, California, Arizona and Texas. Although California’s data report a large backlog of cases, the other three states reported at least 75% less than their peak levels. < / P > < p > some investors regard the flattening of virus transmission curve and the improvement of indicators as a double-edged sword. From the perspective of human health, it is a good thing, but in theory, the good news may affect the stimulus negotiations in Washington.