Big gains keep coming for Alibaba (NYSE:BABA) shareholders. China's leading online marketplace operator is scorching hot, hitting new all-time highs on Wednesday. Alibaba stock keeps building on this year's massive gains, moving higher this month following strong fiscal second-quarter results and a blowout performance during the annual Singles' Day shopping holiday.

Alibaba has soared 116% so far in 2017, more than doubling its market cap to a whopping $486 billion. You don't normally see companies with market caps this massive making moves this big in a single year, but Alibaba isn't even the most valuable Chinese company to have more than doubled this year. It's clearly been a great year for investors in most of China's dot-com darlings. 

Alibaba logo with a Global trade starts here tagline.

Image source: Alibaba.

Climbing the great wall of worry

You don't more than double without attracting detractors. Muddy Waters, Mark Cuban, and even an Alibaba-bashing blogger going by the name Deep Throat have recently talked down the stock's meteoric rise. There were more than 123.2 million shares of Alibaba sold short when the month began.

Alibaba's putting out some impressive financial results despite the growing ranks of worrywarts. The 61% top-line increase it posted earlier this month is its strongest quarterly showing in more than four years. The only thing that the market likes more than growth is more growth, and on that front, we saw Alibaba jack up its full-year guidance this month.The company behind China's Taobao and Tmall marketplaces now sees 49% to 53% in revenue growth for all of 2017, up from the 45% to 49% that it was targeting earlier. 

Alibaba's strong quarter and rosier outlook came before its jaw-dropping performance on Singles' Day, the Nov. 11 celebration that it trademarked as a shopping holiday several years ago to celebrate being single -- hence the 11/11 date. Alibaba generated $25.3 billion in gross merchandise volume on Singles' Day, 39% ahead of last year's showing and a figure that was called into question by Muddy Waters and Blogspot's Deep Throat. 

The e-commerce giant's reach is undeniable. It has reached 488 million active customers over the past four quarters. Several analysts have been jacking up their price targets in recent weeks, keeping up with the perpetually improving fundamentals. 

Alibaba stock isn't cheap on an absolute basis, trading at 38 times this fiscal year's projected profit and a still-steep 29 times next year's analyst profit target. However, it is growing faster than those multiples at the moment. Some of the Alibaba bashers have been wrong all the way up, and while the stock gains only stretch their valuation arguments, one can also argue that if the metrics they claim are too good to be true are legit, then we may just be scratching the surface on the stock gains. Alibaba's on a roll in 2017, and momentum is still on the side of the bulls.