Tesla's Bitcoin investment has paid off so far.
On paper there is a book profit of almost a billion dollars.
But financial market experts are skeptical of the development.
Tesla boss Elon Musk is considered a big Bitcoin fan.
In January, the e-car maker invested 1.5 billion euros in cyber currency.
But leading financial market experts are irritated and demand an investigation by the US stock exchange regulator.
Palo Alto / Munich - Tesla boss Elon Musk has apparently really cleared away with his Bitcoin investment.
According to calculations by Spanish tech journalist Alex Barredo, the electric car maker paid an average rate of around $ 34,900 per Bitcoin in January.
With a total investment of 1.5 billion dollars, the Californians would have acquired around 42,000 Bitcoins.
With the entry of Tesla, the price increase of the crypto currency has accelerated again significantly.
On Monday (January 22nd), Bitcoin was trading at around $ 55,250.
The investment brought the Californians an increase in value of almost $ 890 million - in barely six weeks.
Bitcoin: Tesla entry causes criticism worldwide
The advance is causing growing criticism among experts.
"Tesla's Bitcoin entry fulfills the criteria of market manipulation," recently explained the world-famous financial market expert Nouriel Roubini.
It was "irresponsible and criminal" to buy Bitcoin yourself first and then to inflate the price with a message from the company, ruled Roubini and called on the American Securities and Exchange Commission to intervene.
Roubini, who, because of his critical assessments of the stock exchanges worldwide, is also known as Dr.
Doom (Dr. Untergang) is known as one of the biggest crypto critics.
In the past, the professor at the University of New York had repeatedly warned about the art currencies.
A "gigantic speculative bubble" is emerging here, explained Roubini.
Bitcoin: Allianz chief development sees signs of a crash
It was only on Friday that Allianz boss Oliver Bäte expressed his unease about developments.
"We are very concerned about the issue of financial market stability," said Bäte at the annual press conference.
"Some celebrity buys some Bitcoin and then the prices for these assets explode," said the CEO of Europe's largest insurer.
The development is similar to the situation before the 2008/09 crash and the crash of 2000, warned Bäte.
With assets under management of over 1700 billion euros, Allianz is one of the largest capital investors on the Old Continent.
The cryptocurrency is also coming under increasing criticism because of its power consumption.
According to calculations by the University of Cambridge, the Bitcoin energy requirement per year is at the level of Norway.
Bitcoin: Elon Musk fuels hype
A good two weeks ago, Tesla announced in a mandatory notification to the American Securities and Exchange Commission that it had invested a total of 1.5 billion dollars in Bitcoin in January.
In addition, Bitcoin will soon also be accepted as a means of payment, it said.
The announcement had further accelerated the soaring of the cyber currency.
Musk had previously fueled the hype about Bitcoin via Twitter.
In December, he added the hashtag Bitcoin to his profile overnight.
Shortly thereafter, he fueled speculation with a Bitcoin meme on the short message service.
