Major investor Prosus has written off its 9.6% stake in Indian edtech firm Byju’s to zero, signaling a loss of confidence in the once-promising startup.

Prosus, the largest external investor in Byju’s, disclosed the adjustment in its assessment of Byju’s worth on Monday. Prosus wrote off the startup “due to the significant decrease in value for equity investors,” it said.

Prosus invested about $500 million in Byju’s over the years. It never sold any share in the Indian edtech startup, whose valuation climbed to as high as $22 billion early last year.

More to follow.