Shares in Chinese tutoring firms tumbled Monday after Beijing unveiled reforms that will make a huge change to how they do business.

Arguing that the sector had been "hijacked by capital," officials said it would prevent firms teaching school curriculums from making a profit, raising capital or going public.

While the move – which also bans teaching on weekends and during holidays – is aimed at reducing pressure on children, parents and teachers, it is a gut punch to the tutoring industry, which was reflected in Monday trading.

Shares in New Oriental Education & Technology Group Inc. plunged by 47 percent in Hong Kong, deepening Friday's record 41 percent fall that came as speculation about a crackdown spread on social media.

Its U.S.-traded shares shed by 54 percent.

The company said in a statement on Sunday that it expected the new measures "to have a material adverse impact on its after-school tutoring services related to academic subjects in China's compulsory education system".

Another firm, Koolearn Technology Holding Ltd. closed by 33 percent down, while China Maple Leaf Educational Systems fell 10 percent.

Businessmen lost their billionaire statuses as shares were hammered.

New Oriental CEO Yu Minhong lost his billionaire status, shedding $685 million to leave him with $579 million.

And Zhang Bangxin's fortune fell $2.5 billion to $1.4 billion, Bloomberg News reported, after his New York-listed TAL Education Group fell 71 percent.

The private education sector was worth $260 billion in 2018 according to consultancy and research firm L.E.K. Consulting, driven by China's hyper-competitive kindergarten-to-university education system in cities.

JPMorgan Chase analysts said it was uncertain whether firms could continue to be traded on stock markets. "In our view, this makes these stocks virtually uninvestable," it said.

(With input from AFP)