Gautam Adani faces a pivotal day on Monday as his flagship company’s $2.5 billion share sale bids for the second day of a $48 billion plunge in the Indian billionaire’s stock sparked by a report of US short sellers covered up.

The market capitalisation of seven listed companies in the Adani group, led by Asia’s richest man, fell sharply after a Hindenburg Research report last week showed concerns about high debt levels and tax havens.

Adani Group issued a detailed response late Sunday, saying it complies with all local laws and has made the required regulatory disclosures. It called the report baseless and said it was considering action against Hindenburg.

The stock market crash is a dramatic setback for Adani, 60, a school dropout whose meteoric rise in recent years to become the world’s third-richest man slipped last week on the Forbes rich list to seventh place.

Adani Enterprises’ secondary share sale, which opened to retail and institutional investors on Friday, was only 1% subscribed as the company’s shares fell 11% from their minimum offer price.

Adani Group told Reuters in a statement on Saturday that while media reports said bankers for the country’s most extensive secondary share offering were considering extending the timeline beyond January 31 or adjusting prices due to the drop, but still sold at the planned issue price.

Some of Adani Group’s shares have soared more than 1,500% in the past three years, driven by aggressive expansion in businesses including ports, power generation, airports and mining.

Adani Enterprises has set the floor price for the secondary offering at Rs 3,112 per share, with a ceiling of Rs 3,276 – well above Friday’s close of Rs 2,761.45.

Indian regulations state that a share issue must be at least 90% subscribed; if not, the issuer must refund the total amount.

Maybank Securities and Abu Dhabi Investment Authority were among the investors bidding to issue the anchor tranche.

On Saturday, index provider MSCI said it was seeking feedback from market participants on Adani and was monitoring factors in MSCI’s indexes that “may affect the eligibility of these underlying securities.”

There are at least six Adani Group companies in the MSCI India Index with a cumulative weight of 4.31%.