A few words of caution. First, never believe the buy/hold/sell ratings from banks, they don't actually mean buy or hold or sell. I suggest reading this for a quick explanation of how sell-side equity research works: https://www.bloomberg.com/view/articles/2017-01-20/wall-street-analysts-give-investors-what-they-want
Second a stock split cannot change the value of a company. If you think AMZN is a good value after the stock splits it is an equally good value today. 477M shares at $845 gives a market cap of $403B, if they split 2-for-1 you have 954M shares at $422.50 which is still a $403B market cap.
On a stock specific note I disagree with your assessment of Amazon. The retail business has negative working capital so when it was growing rapidly they could reinvest that float into other business areas. As that growth slows they lose that excess cash for investment. With the exception of cloud services they continue to invest in low margin or no margin businesses that don't earn an ROIC above their cost of capital. Growth without profitability is value destructive. Groceries are a terrible business, the music and video offerings have escalating costs and Amazon has no competitive advantage in either of them. Nobody is making money in the restaurant take-out business. At 172x P/E (think of a bond with a 0.58% interest rate and no guaranteed payout), 3x Sales and 34x EV/EBITDA you are betting everything on profitability 10+ years in the future. Maybe you'll be right but there are many other, lower-risk options out there in my opinion.