A little-known Hong Kong-based fintech company has exploded on the New York Stock Exchange, rising more than 21,000 per cent in less than three weeks.

Just two days ago AMTD Digital was trading at a peak of US$1679 ($2678) after debuting on the exchange on July 15 at a price of US$7.80.

AMTD Digital is an arm of Hong Kong investment bank AMTD Idea Group and trades under the ticker symbol HKD.

It was founded in 2019 and, according to regulatory filings, brought in just over US$25 million in revenue for 2021.

Despite this, the company surged to a market cap of more than US$425 billion at its peak this week, making it one of the most valuable companies in the US and putting it ahead of the likes of Disney, Coca-Cola and McDonald's.

The sudden surge has left many scratching their heads, with AMTD Digital itself even saying there appeared to be no "material circumstances" behind the surge.

"During the period since our initial public offering, the Company noted significant volatility in our ADS price and, also observed some very active trading volume," the company said in a statement.

"To our knowledge, there are no material circumstances, events nor other matters relating to our Company's business and operating activities since the IPO date."

It appears the stock has now begun to fall, trading at US$1100 at the time of publication.

Some have drawn comparisons to the meme stock mania last which saw record rising in shares of companies like GameStop, with social media platform Reddit central to the craze.

This means that many are once again questioning whether popular subreddit WallStreetBets is behind the rise, however it is still unclear whether that is the case.

Chief investment officer at China-focused ETF provider KraneShares, Brendan Ahern, said AMTD was "in some ways the perfect meme stock".

"It's a combination of a few things — a small float, some likely short interest and now the meme stock angle," he told Forbes.

A quick search of Reddit's WallStreetBets shows AMTD has only been mentioned in the group within the past two days, with many furious at the suggestion the page had something to do with the rise.

"The fact that all news sources have pointed the finger at retail investors is horrifying. How in God's name would they have enough money to make a company bigger than Disney?" one user wrote.

"No one seriously believes that. Market cap hit like 500b … Do they seriously think that a bunch of part time Wendy's employees could do that?" another person questioned.

Another added: "I tried to buy it, brokerage won't let me, how am I contributing to this fiasco?"

The GameStop saga of 2021

In what seemed like a modern day twist to the Robin Hood story, last year video game retailer GameStop became the battleground between the rich and the poor after Reddit users attempted to bankrupt hedge fund managers.

The company experienced a decline in physical sales due to the Covid-19 pandemic, with the stock hovering between US$3 and US$10 for much of 2020 as a result.

This all changed in early 2021 when the stock price hit multiple straight days of increases.

At one stage its stock was priced higher than Apple, Facebook, Microsoft and Disney, as it surged by 93 per cent with its shares climbing above US$300.

Individuals investors, many from the Reddit sub group, drove the share price up using an app called Robinhood. It lets anyone trade stocks without commission.

Billionaire Elon Musk added more fuel to the fire when he tweeted a link to the Reddit message board, which saw GameStop's stock up nearly seven times its value from where it was less than a month previously.

Overall, shares rose about 1000 per cent over a two-week period.

The feud started after word spread on the Reddit group that a hedge fund was planning to short sell GameStop's stock.

As a result, users decided to get their own back with what is described as a bull raid. They bought up stock before it could drop in price and rapidly inflated its value.

It meant all those traders who had bet on a decline in value were losing serious amounts of cash.

Hedge fund Melvin Capital was nearly ruined after it made huge bets that GameStop stock would crash.