For various reasons, high volume trading over the past 20 days is starting to further suggest it is time to buy a few top-rated Zacks stocks.For investors, high trading volume is preferable in a stock because it typically correlates with less volatility and can be indicative of more buyers in the market. This can propel stocks higher and here are three to consider at the moment when pondering this scenario.Amazon (AMZN) Bullish price targets for Amazon have made shares spike over the last week with an avera ...