Share prices for EV startup VinFast are proving to still be incredibly volatile following a bumpy start. On Monday, the automaker’s shares were higher than ever, bringing its overall value to more than that of GM, Ford, VW, or Mercedes-Benz, per investors.

VinFast first started trading on the NASDAQ exchange on August 15 with an opening price of $22 per share. The price quickly rocketed up to a value of $38.78, before falling back down to $13.94 later in that same week.

However, by Monday, August 28, the price had risen to $89, reports Bloomberg. That suggests that VinFast is worth $200 billion, making it the third-most valuable automaker on earth, behind Tesla and Toyota, and worth more than Goldman Sachs and Boeing.

Read: After Stratospheric Start, VinFast Stock Comes Crashing Back To Earth

 Roller Coaster Ride Continues: VinFast Now Apparently Third Most Valuable Automaker On Earth At $200 Billion

Naturally, there are some caveats to that valuation. For one thing, those companies have much more reliable stock prices. For another, VinFast’s founder Pham Nhat Vuong still controls 99.7 percent of the company’s shares. That means that only a tiny minority of stock is available to investors, which tends to breed the kind of volatility we see here.

Moreover, there are serious questions about the automaker’s ability to compete in big markets like the U.S. Although VinFast has proven that it can actually manufacture large volumes of EVs (something that sounds easier than it is), it has only managed to sell 137 vehicles in America this year.

Moreover, the quality of the vehicles has been questioned by North American automotive critics. It also struggled to make internal combustion engine vehicles for years before finding some success in Vietnam with electric vehicles.

All of which has led some analysts to tell investors to sell their stock, reports Investor Place. While it would be pessimistic to suggest that the automaker is doomed to fail, its stock price seems to have little to do with how realistic its chances of success truly are. That has led some experts to proclaim the performance of the shares to be a “bubble” that could burst at any moment.

 Roller Coaster Ride Continues: VinFast Now Apparently Third Most Valuable Automaker On Earth At $200 Billion