HSBC and BlackRock have marked down their valuations of BYJU'S, once worth $22 billion, to zero. BlackRock, which cut the edtech startup's valuation to about $1 billion last year, has now written off its investment. Meanwhile, HSBC said the value of Prosus' 10% stake in BYJU'S is now nil due to the startup facing "multiple legal cases and funding crunch".