By Bret Kenwell Amazon stock is rallying after announcing a stock split. Here’s how to trade it now. Amazon (AMZN) – Get Amazon.com, Inc. Report stole the headlines — at least for a few moments — on Wednesday after the close. That came as the company announced a 20-for-1 stock split and a $10 billion buyback plan. Given its $1.4 trillion market cap before today’s mild 5% rally though, the buyback is less of a focus vs. the stock split. Investors have been clamoring for a stock split from Amazon for years but have strongly called for it over the last 12 months or so. Unfortunately, some are won…