Per CNBC

Nasdaq is hitting the pause button on initial public offering (IPO) preparations for at least four small Chinese companies. An investigation has been launched into the odd stock rallies of similar firms following their debuts.

The decision comes amidst a surge in Chinese companies, with $50 million or less rising to 2,000% before nosediving a few days later.

An Ellenoff Grossman & Schole LLP corporate and securities attorney was informed that they would continue to hit the pause button until they determine the cause of the aberrational trading activity earlier this year.

Data from Dealogic estimates that Chinese IPOs in the US returned an average of 426% on the first day of trading compared to 68% for other IPOs.