What happened

On one of the better days for the stock market in recent times, Amazon (AMZN 1.49%) was a standout. On a general resurgence in tech stocks and a very positive new analyst note, the giant online retailer's stock zoomed more than 5% higher on Wednesday, easily topping the 1.5% gain of the bellwether S&P 500 index.

So what

The tech rally was certainly a tailwind for Amazon at the end of the day, but investors were probably more encouraged by that research note. It was written by JPMorgan Chase analyst Doug Anmuth, who shared a very heartening update on the company's Prime loyalty program.

Following what he calls a "deep dive" into Prime's present and future, Anmuth came up with a new estimate of the program's value to its subscribers. All told, according to his calculations, Prime membership confers roughly $1,100 in annual benefits, such as free shipping and savings on items like drug prescriptions. This makes it quite the compelling value proposition even at the recently increased rate of $139 per year.

It also makes it an increasingly more attractive add-on for Amazon customers. Again according to his estimates, Anmuth says those yearly benefits totaled around $1,000 in 2020, and only approximately $544 in 2016.

Now what

Not surprisingly, the prognosticator is very bullish on Amazon stock. With his new take, he's maintaining his overweight (buy) recommendation on it, at a price target of $200 per share. This level is nearly double that of the stock's most recent closing price, even after Wednesday's pop.