Amazon may reach the $1 trillion market value milestone in the next year, according to a top Wall Street firm.

Morgan Stanley reiterated its overweight rating for Amazon shares, presenting a "bull case" 12-month price target of $2,000 per share or roughly a $1 trillion market cap.

"Amazon's high margin [revenue] disclosure speaks to the $1trln ($2,000/sh) sum of parts bull case," analyst Brian Nowak wrote in a note to clients Sunday entitled "The Math Behind the Trillion Dollar Bull Case."

"Our sum of the parts methodology looks out to 2022 for the 5 various segments (1P, 3P, AWS, Subscription, and Advertising/Other) and applies multiples based on what we view are appropriate peer groups, factoring in relative growth rates and margin profiles. We discount each segment back to year-end 2018 to arrive at a $2,000/share value or ~$1 trillion bull case."

Nowak shared his valuation methodology and key forecasts for each of Amazon's businesses to reach the $2,000 share price target.

The analyst valued Amazon's core retail business at $600 billion, estimating 13 percent annual sales growth for its e-commerce business in 2022 and a 5.5 percent operating profit margin that year. He also estimates its third-party marketplace business will achieve a 25 percent earnings before interest, tax, depreciation and amortization (EBITDA) profit margin in five years.

Nowak gives a $270 billion valuation for Amazon Web Services, the company's cloud computing arm, forecasting 18 percent annual sales growth and a 50 percent EBITDA margin in year 2022. He also assigns a $70 billion value to the company's growing subscription business and $55 billion for its advertising segment.

Even as he outlined the positive optimistic scenario, the analyst reiterated his $1,250 price target for Amazon shares, representing 11 percent upside to Friday's close.

Amazon shares have rallied 50 percent year to date through Friday, compared with the S&P 500's 15 percent return.

